1.Introduction #


Plural Component Proportioners


BOSS SERIES PROPORTIONERS: 5/6K, 5/12K, 6/6K, 6/12K SERVICE MANUAL Revision 2 December 6, 2017 Not approved for use in explosive atmosphere locations.


Important Safety Instructions: Before operating any BOSS Series Proportioner, carefully read this manual. All of the information is provided for the proper operation and troubleshooting of the BOSS Series. Pay close attention to any safety warnings, and save these instructions for further technical and informational reference.

Last updated on April 7, 2018

2.Safety Precautions and Warnings #


See pages 3-4 of existing BOSS Manual and pages 5-7 Graco A25 Manual

This chapter contains important information on the safety, handling, and use of your BOSS Series Proportioner.

Last updated on April 2, 2018

2.1.Fire, Electric Shock and Explosion Hazard #

High Voltage components can cause electric shock. Combustible materials and fumes in confined work areas can ignite and explode. To help prevent explosion, fire and electric shock:
  • Shut off all power before opening or servicing any part of proportioner.
  • Ensure that all electrical wiring and service is done by qualified personnel and complies with local codes.
  • Use equipment in well ventilated areas.
  • Eliminate all ignition sources.
  • Keep work areas free of solvents, rags, gasoline and other debris.
Last updated on April 2, 2018

2.2.Skin Injection Hazard #

High pressure fluid from spray gun, ruptured components, or leaks will pierce skin. This may look minor but is a serious condition – Get immediate emergency treatment!

  • Do not point spray gun at anyone or any part of body.
  • Do not place hand or fingers over gun tip.
  • Use lowest possible pressure when troubleshooting or flushing equipment.
  • Check hoses, connections and fittings daily.  Tighten or replace loose or worn or damaged parts immediately.
  • Relieve all pressure from proportioner and all components when you stop spraying and before cleaning or servicing equipment.
Last updated on April 2, 2018

2.3.Personal Protective Equipment #

You must wear proper protective equipment when operating, servicing or when in the operating area of equipment.  This will protect you from serious injury including but not limited to: eye injury, inhalation of toxic fumes, and loss of hearing.

This equipment includes but is not limited to:

  • Protective eyewear
  • Respirator, gloves, and clothing recommended by fluid and solvent manufacturer
  • Hearing protection
Last updated on April 2, 2018

2.4.Burn Hazard #

This equipment is used with heated fluid which is hot and will cause some surfaces on equipment to become very hot. To avoid burns:

  • Do not touch fluid or equipment.
  • Allow fluid and equipment to completely cool before touching or servicing.
  • Wear gloves and protective clothing.
Last updated on April 2, 2018

2.5.Toxic Fumes and Fluid Hazard #

  • Read Material Safety Data Sheet (MSDS) to know specific hazards of fluid you are using. (provide sheet for download?)
  • Handle and store hazardous fluids according to applicable guidelines.
Last updated on April 2, 2018

2.6.Misuse of Equipment Hazard #

Misuse can cause serious injury or death!
  • For professional use only.
  • Do not exceed the maximum temperature rating or working pressure of equipment.
  • Check equipment daily replacing worn or damaged parts immediately.
  • Read manuals, warnings, and labels before operating equipment.
  • Use only compatible fluids/solvents.
  • Keep hoses away from traffic areas, sharp edges and hot surfaces.
  • Comply with all safety warnings and labels.
  • Service of equipment should be done by qualified personnel only.
Last updated on April 2, 2018

2.7.*Toxic Fluid or Fumes Hazard #

*Nothing Listed in content*

Last updated on April 17, 2018

2.8.*Equipment Misuse Hazard #

*Nothing Listed in content*

Last updated on April 17, 2018

2.9.*Thermal Expansion Hazard #

*Nothing Listed in content*

Last updated on April 17, 2018

2.10.*Moving Parts Hazard #

*Nothing Listed in content*

Last updated on April 17, 2018

3.Important Plural Component Information #

Insert Warnings:

  • General Warning
  • Toxic fluid or fumes hazard
  • Protective Equipment Warning
  • Fire and Explosion Hazard


See Graco A25 Manual p. 8 & 9 – no content shown (advise direction on this)


Isocyanates are catalysts used in two component spray foams and polyurea coatings.  This product is commonly referred to as ISO or A side. When ISO is exposed to moisture, it begins to react by forming small crystals that become suspended in the fluid.  After prolonged exposure, a film is created on the surface of the fluid and the ISO begins to thicken into a gel. This adversely affects the performance of the ISO as well as puts added stress on the wetted parts of the plural component system.

  • To prevent exposing ISO to moisture: Always use a sealed container with transfer pump securely fastened.
  • Keep vent in container closed or use a desiccant dryer if needed.
  • Keep the solvent cup of the fluid pump filled with SFE pump lube, part no. SFE-410. This removes any excess fluid on pump shaft to prevent material from hardening when exposed to moisture.
  • Always park pumps in down position to eliminate any chance of moisture contact with ISO residue that may be on pump shaft.
  • Never use reclaimed ISO as it is not possible to determine if it has been exposed to moisture.
  • Never store ISO in an open container.
  • Use only spray hoses that are moisture resistant and designed for use with plural component systems.
Last updated on April 17, 2018

4.Typical Installation with Circulation #

  1. Proportioner
  2. Spray Hose
  3. Supply Lines
  4. Recirculating / Pressure Relief Lines
  5. Barrel Pumps
Last updated on April 2, 2018

5.Circulating Fluid Through the System #



If there are ISO and RESIN components within the system, it is absolutely vital that the material is recirculated every two weeks if the machine is not in use! Failure to properly circulate material may cause permanent damage to hose, supply lines, recirculating lines, and machine!

Insert Warnings:

  • General Warning
  • Electric Shock
  • Skin Injection Hazard
  • Burn Hazard
Follow these steps to properly recirculate material through system:
  1. Turn on all breakers for hose heat and pre-heaters on machine.
  2. Turn compressor on to supply air to transfer pumps. Do NOT turn on switch to pressure up air motor! Use only transfer pumps to circulate material through system.
  3. Remove gun from manifold.
  4. Circulate fluid through entire system and out of manifold ports back into supply drums. Allow to circulate for five minutes per side.
  5. Close all ports on manifold.
  6. Replace spray gun on manifold.
  7. Open pressure relief valves on preheaters to allow fluid to flow through recirculating line back to supply drums. Allow to circulate two minutes per side.
  8. Close pressure relief valves.
  9. Turn compressor off to discontinue air supply to transfer pumps.
  10. Turn off all breakers for hose heat and pre-heaters on machine.
Last updated on April 2, 2018

6.Component Identification #


  1. A Side Pre-heater
  2. B Side Pre-heater
  3. Recirculating / Pressure Relief Valve
  4. Air pressure regulator (controls fluid operating psi)        
  5. Fluid operating pressure gauge   
  6. Temperature controller        
  7. Pump switch        
  8. Breakers        
  9. A side outlet     
  10. B side outlet     
  11. Voltage leads for hose heat     
  12. Temperature Sensing Unit (TSU)     
  13. Air connection for spray gun     
  14. Air Motor     
  15. Stroke Counter
  16. Fluid Pump (See Illustration Below)

Last updated on April 2, 2018

6.1.Wiring Diagram Component Identification #

A = System Power Switch

B / C / D = Breaker Switches that provide power to the B-side, A-side, and Hose Heating Systems

E / F / G = B-side, A-side and Hose Heat Controllers used to set and monitor temperatures.   System inputs in to each controller reports actual temperatures & the controller sends a “charge” to the appropriate Relay when heat is needed

H / I = A-side and B-side Heater Relays.  Relays receive a “charge” from the Controllers when heat is required then sends power to the A-side and B-side Heaters.  NOTE:  The Hose Heat Relay is in the base of the unit

J = Mini Transformer that converts 240V to 24V

K / L = Ice Cube Relays that receive signals from the reverser magnets and sends it to the Air Valve which redirects the air flow

M / N = Large and Small Terminal Strips that are essentially wire connectors

O = Fluid Pump Switch On / Off – Activates the Air Motor that pumps material down the hose or recirculates back to the source

Last updated on April 2, 2018

6.2.Fluid Pump Shaft #

Last updated on April 2, 2018

6.3.Fluid Pump Foot Valve #

Last updated on April 2, 2018

7.Setting Up Your BOSS Proportioner #

Before installing the BOSS Series Proportioner and start-up, carefully read all the technical and safety documentation included in this manual. All of the information is included for user safety and avoiding possible breakdowns from the incorrect use of the BOSS Series Proportioner.

1. Mount machine in a dry, level area away from moisture

Electrical requirements for BOSS Proportioner:

  • Input Voltage: 1 phase, 240V AC, 50/60hz
  • Amperage Requirements: 67Amp max load

**See Technical Data sheet on page ? for more details.

2. Connect a 6 AWG (2 wire + ground) electrical cord to main breaker, which is located in upper housing of machine



3. Connect transfer pumps


  • Install barrel pumps in component A (Isocyanates) and B (Resin) supply drums.
  • Install air mixer in component B drum.  Only mix if resin contains water as the blowing agent.
  • Connect ¾ in. supply hoses between barrel pumps and fluid inlet on proportioner.


4. Connect recirculating/pressure relief lines


  • We recommend using a high pressure return line to connect the pressure relief valves to the barrel pumps. (Please see p. ?)
  • An optional connection would be a relief line from the pressure relief valve to a grounded and sealed waste container.


5. Connect heated spray hose


  • Connect the hose assembly to the fittings coming out of each pre-heater that face forward and inward on each side of the front of the machine (red to A side on left pre-heater and blue to B side on right pre-heater).
  • Connect the electrical connectors on the two red #6 gauge wires coming out of the front of the proportioner base to the two #6 gauge wires on the hose assembly.
  • Connect the heat sensor wire from proportioner to heat sensor wire on hose (secure with wire connectors, tape and insulate connections).

  • Pull back the scuff jacket on the spray hose approximately 6 feet on the gun end.  A purple sensor wire will protrude from the insulation on the hose. Cut the end of the purple sensor wire that runs the length of the hose and connect it to the short wire coming out of hose insulation.

  • Twist, secure with wire connectors, and insulate as before.  Pull the scuff jacket back to the end of hose and tape.

  • There are two red #6 gauge wires protruding from gun end of spray hose.  These two wires should be connected using an electrical connector sized for #6 gauge wire.  Tape this connection neatly to hose


6. Connect gun to spray hose


  • Close gun fluid manifold valves.
  • Connect red to A side and blue to B side.
  • Pressure check hose. Check for leaks. If there are not leaks, wrap hose and electrical connections to prevent from damage.


7. Determine appropriate transformer lead


  • Remove the access panel from the left side of unit on the bottom which reads SFE. Use the chart below to determine the lead that is appropriate for desired hose length. This lead should be connected to the end of the fuse facing you. If it is not connected, connect it now. (Leave this panel off for now)

Voltage guidelines for recommended hose temperature:

To test amperage to make sure the correct voltage is going to the hose, place a clamp amp meter on one of the red wires coming out of the front of machine.  The AC amps should read between 38 and 55.  If the amperage is higher than 55, connect the next lowest voltage lead wire from the transformer to the fuse block in bottom of machine. If it is below 38, connect the next highest voltage lead. (See Figure 10 above for voltage connection guidelines)


Last updated on April 17, 2018

8.Initial Startup #

Follow the recommended procedures in the order shown.


1. Check that setup process is complete



2. Make sure all hoses, cables and connections are properly connected (Some jolting and jarring may have occurred during shipping)

3. Check pump lube levels in solvent cups and resupply if necessary

4. Connect air supply to barrel pumps

  • Turn on air mixer to B component material. If using a foam that contains water as the blowing agent, it is recommended to stir the B component for 20-30 minutes before spraying.
  • Turn both input valves on proportioner to the “on” position. (Handle in line with the hose)

  • Hold gun fluid manifold over two waste containers. Open fluid valves A and B until clean, air-free fluid comes from valves.
  • Close valves.


5. Set temperatures


  • Turn all breakers to the “on” position. The numbers that appear on the controllers are the actual temperatures.
  • Hold down the left button on the top controller (hose heat controller) and press the “up” arrow button the far right. This will increase the target temperature. For best results, set according to the chemical manufacturer’s recommended temperature. The bottom two (A and B side pre-heater) controllers should be set in an identical manner. The indicator lights and the LED indicator lights to the left of controller indicate pre-heaters are heating. Allow 20-30 minutes to heat up to working temperatures.


6. Set pressure


  • Turn the toggle switch on (up position).
  • The gauges on the pre-heaters display the working pressure. Adjust air regulator until each pre-heater pressure gauge is registering approximately 800psi. (Pressure may be adjusted on the regulator assembly to increase/decrease this pressure.)
  • The pressure may need to be bled off of either the A or B side so that the pressure on each gauge is the same.

(Which warning symbol to add here with text below? Skin Injection warning?)

Insert Warning Symbol and text box around the following text.
 Do not allow the pressures of the A and B side to have a variance of more than 200 psi. If this occurs, material may “crossover” at the gun.

Last updated on April 17, 2018

9.Preparing Gun for Spraying #

1. After reaching spray temperatures, engage gun safety lock

2. Attach gun fluid manifold and attach air line. Open the air valve at gun

Need photo or line drawing of this step. (Which picture am I using?)

3. Open gun fluid manifold valves A and B (turn counterclockwise)

         Need photo or line drawing of this step. (Which photo am I using?)

4.Disengage gun safety lock

5. Check fluid pressure gauges at preheater to ensure proper pressure balance. Adjust fluid pressure as needed

(Illustration needed – Please provide)

6. Test spray onto cardboard. Adjust temperature and pressure for desired spray pattern

7. Equipment is now ready to spray

Last updated on April 17, 2018

9.1.Spraying Material #

Use this section for setting up the BOSS Gen 2 Gun for spraying and adjustments.

Last updated on April 17, 2018

9.2.Spray Adjustments #

Spray Adjustments

  • Flow rate, atomization, and amount of overspray are affected by four variables.

Fluid pressure settings

  • Too little pressure results in an uneven pattern, low flow rates and poor mixing.
  • Too much pressure results in excessive overspray, high flow rates, difficult control, and excessive wear.

Fluid temperature

  • Effects are similar to fluid pressure settings.

Mixing chamber size

  • Choice of missing chamber is based on the desired flow rate. See manufacturer for further information.

Cleanoff air adjustment

  • Too little cleanoff air results in droplets building up on the front of the nozzle, and no pattern containment to control overspray.
  • Too much cleanoff air results in air-assisted atomization and excessive overspray.


Last updated on April 17, 2018

10.Procedures #

Last updated on April 17, 2018

10.1.Daily Shutdown Procedure #


1. Follow gun shutdown procedure


  • It is critical to clean gun at the end of every working day, or when the machine is not in use for an extended period of time. Refer to spray gun literature for shutdown and cleaning procedures.


2. Turn off hose heat



3. Turn off A and B pre-heater breakers



4. Turn pressure toggle switch to “off” position



5. Bleed pressure from the system with the recirculating/pressure relief valves until cylinders are in the “down” position

  • See pressure relief procedure (in Startup, section 5)


Caution: To avoid possible Pump Seal Weepage and moisture vapor drive into the Heated Hoses, the system pressure should not be reduced to zero. It is recommended to lower the system pressure to a minimum of 400 psi.

Bleed pressure very slowly to avoid pump seal damage. If cylinders remain in the “up” position, it may be necessary to switch the toggle off/on one time to cycle the pumps downward. The pump needs to be “parked” in the down position to avoid ISO hardening on the A-side shaft. Pressure may also be bled off by spraying the gun, or through the side blocks if they are not attached to the gun, by opening the ball valve.


6. Turn off main power



7. At the end of the day, make sure the pumps are in the bottom retracted position.

  • Put a small amount of DOP (Also known as pump lube or TSL or throat seal liquid) in the lube cup on top of the A-side pump to ensure that no ISO material will harden on the pump shaft causing a seal failure. The B-side pump should also be lubed initially, but isn’t as critical as the A-side and won’t harden.


Caution: Remember! Parking or retracting your pumps and fresh pump lube at end-of-day shutdown is the most important daily maintenance procedure of the BOSS Proportioner.


Last updated on April 17, 2018

10.2.Pressure Relief Procedure #


1. Turn off feed pumps and agitator, if used

2. Shut off pump pressure toggle switch

3. Slowly bleed pressure off both A and B side pressure relief valves

4. Park fluid pressure pumps in down position to avoid ISO hardening on A-side shaft.


Last updated on April 17, 2018

10.3.Flushing Procedure #

1. Flush out old fluid with new fluid, or flush out old fluid with a compatible moisture-free solvent.

2. Use lowest possible pressure when flushing.

3. Put barrel pump into solvent desired to flush system.

4. Turn barrel pump air pressure on.

5. Put recirculation lines into waste container to catch old material.

6. Open pressure relief valve.

7. Pump new fluid through system until it appears in waste container.

8. To flush entire system, circulate through gun fluid manifold (with manifold removed from gun).

9. Always leave DOP (Dioctyl Phthalate) or a non-water based, non-water absorbent fluid in system. Do not use water.

Last updated on April 17, 2018

11.Hose Heat #


The hose temperature is set on the Hose Heat Controller by pressing and holding down the left button while adjusting the set temperature with either the up/down arrow buttons.

Whenever the hose temperature drops below the set temperatures, a green light blinks in the upper left corner of the Hose Heat Controller. This light indicates the controller is sending a message to activate the hose heater. The two red wires that come out of the front of the proportioner (circled in yellow on photo) provide heat to the hose.

One of the red wires attaches to a corresponding red wire that is on the A-side hose and the other to the red wire from the B-side hose. These two wires run the length of the hose and are connected to the 10-foot whip.

The actual hose temperature is read by the purple Temperature Sensing Unit (TSU) wire (see above photo) that runs from the back side of the Hose Heat Controller and down the hose where it terminates under the hose insulation, just prior to the 10-foot whip. This purple wire contains three wires under the purple insulation (purple, red and uninsulated) and measures the hose temperature and reports it back to the Hose Heat Controller.   


Heating material through a hose is inefficient so it is always better to use the material heaters in your proportioner to do the heavy lifting.  It is best to view hose heat as a material temperature maintainer and not as a material heater. It is a good practice to use the material heaters on the proportioner to warm the material slightly above desired application temperature and have the hose heat set to the desired temperature. Doing this will reduce the hose heat usage and energy consumption which will extend the service life of the hose. Always set the preheaters approximately 3-5 degrees more than the hose heat. NEVER set your hose heat higher than preheaters.

  • Note: Always remove the hose completely from the hose rack when the hose heater is activated. Leaving a hot hose on the rack will result in excess heat building up that will damage your hose.



The Hose Heat Controller is where the desired hose temperature is displayed based on the information received from the purple Temperature Sensing Unit (TSU) wire. The Hose Heat Controller compares the set temperature to the temperature reported by the TSE and if the set temperature is lower, a green indicator light will flash in the upper left corner of the controller indicating that it is calling for hose heat.

A signal from the Hose Heat Controller is sent to the Hose Heat Relay to activate the hose heat. The relay is in the base of the unit on the left side. When prompted by the Hose Heat Controller the Hose Heat Relay will complete the circuit supplying full voltage from the Transformer to the red wires that heat the hose. The transformer has a “pigtail” of wires each labeled with a different voltage.

The wire from the “pigtail” that is used depends on the length of hose that is being heated. The chart below shows how to select the appropriate voltage wire for the unit. The lead typically used for a 200-foot hose system is the 64-volt lead wire. In addition, a Zero-volt wire from the Transformer pigtail must also be connected to the Hose Heat Relay as shown below.

Before power can be supplied to the hose, the lead wire from the transformer must first pass through a fuse and the Hose Heat Relay must receive a signal from the Hose Heat Temperature Controller calling for heat. When this happens, the relay will complete the circuit allowing power to flow down the hose. It may simplify the process to view the Hose Heat Relay as a switch. When the Temperature Controller is calling for hose heat, the relay switch is flipped, which completes the electrical circuit enabling power (and heat) to go to the hose. When the controller is not calling for heat, the relay switch is shut off, which interrupts the circuit and prevents power from going to the hose.


Last updated on April 17, 2018

12.Maintenance #

NOTE! To achieve maximum output from the BOSS Series Proportioner, a daily or regular maintenance schedule is required.

The following maintenance is required to achieve maximum output and keep the proportioner in sound mechanical condition. Failure to perform this maintenance may void any manufacturer warranty.

*When machine is parked, flush entire system with compatible solvent to store machine for an extended period.

Last updated on April 17, 2018

12.1.Daily Maintenance Schedule #

  • Check pump lube level in solvent cups.
  • Inspect the machine, supply lines, spray hose, and spray gun to ensure everything is in proper working order and that there are no leaks.
  • Grease gun thoroughly after use to prevent accidental material crossover.
  • Inspect hose and make any necessary repairs to ensure proper performance.
  • Drain moisture from air compressor to prevent any damage to system components.
  • Remove plug on Y inlet before startup and clean as needed.
  • Keep ISO from exposure to moisture by ensuring transfer pump remains secure.
  • Clean check valves on gun.
  • Clean mixing chamber ports on gun and check for side seal wear.
  • Park pump in “down” position after use.
Last updated on April 17, 2018

12.2.Biweekly Maintenance Schedule #

  • Recirculate A-side material throughout entire system (including hoses) every two weeks if machine is not in use.
  • Clean check valves regularly.
  • Clean mixing chamber ports and check for side seal wear.
Last updated on April 17, 2018

13.Troubleshooting #

WARNING! Before correcting any kind of defect, make sure the Main Power Switch is OFF. NEVER access the inside of the Control Panel with the Proportioner power supply ON. The Pneumatic Unit is a component that works under pressure. Do not open any connection or carry out maintenance on components subject to pressure until all pressure has been bled to zero.

CAUTION! Do not exceed the value of the transformer hose breaker.

CAUTION! All repairs performed by unqualified personnel may cause damage to the unit and put the operator at risk.

The BOSS Series Proportioner has been designed and built to withstand severe working conditions with a high degree of reliability, provided it is used in a suitable application by a properly trained operator. The information provided in this chapter will serve as a guideline to detect and resolve problems, should they arise.

Last updated on April 2, 2018

13.1.Basic Troubleshooting #

Last updated on April 2, 2018

13.1.1.Power / Air Troubleshooting #

Verify that the source electrical power and air pressure/volumes are correct and verified by meter or gauge. Check electrical circuit breakers, compressor, etc. Be aware that the potential machine error might be a power/air source error and not the machine.

Last updated on April 2, 2018

13.1.2.Material Troubleshooting #

Material needs to be without debris and preconditioned to 70 degrees Fahrenheit. Drums should be off the concrete floor to prevent cold transfer. For coatings, the B-side should be pre-mixed. Mixer should be lubed regularly and working properly.

Last updated on April 2, 2018

13.1.3.Material Supply System Troubleshooting #

The supply pressure will vary with the type of pumps used and what pressure they’re being fed. With the common 125 psi shop air supply, a 1/1 pump should put out approx. 125 psi of fluid flow and a 2/1 pump should put out approx. 250 psi. The supply pump gauges can be erratic as the pumps cycle depending on the varying viscosities of the material. This is normal. Make sure gauges read at least 50 psi at the low end of the cycle; if it is bouncing off zero, the machine is being starved for material.

Last updated on April 2, 2018

13.1.4.Heated Hose Troubleshooting #

The hose and whip assemblies take the most abuse of any part of the spray system. How they are taken care of will determine the service life. Keep hoses as clean as possible and re-tape/re-insulate as needed. Do not use a coiled hose and do not leave the hose on the hose rack. It will create hot spots and excess heat which will damage the hose.

Be aware of connections that commonly fail: electrical and thermocouple connections, etc.

Last updated on April 2, 2018

13.2.Specific Troubleshooting #

Last updated on April 2, 2018

13.2.1.Fluid Pressure Issues and Problems #

See below for ways in troubleshooting Fluid Pressure issues

Last updated on April 2, 2018 Proportioner is not building fluid pressure #



  • General Warning
  • Toxic Fluid or Fume Hazard
  • Personal Protective Equipment
  • Skin Injection Hazard
  • Pressurized Aluminum Parts Hazard
  • Moving Parts Hazard


It is important to know which direction of the stroke the machine is losing pressure on. If machine is losing pressure on the “down” stroke, the problem is either debris lodged in lower check ball of pump causing the check ball not to seat.

  1. Disassemble pump and check lower check ball and seat.
  2. Clean and reassemble.

If machine is losing pressure on the “up” stroke, there are two possible causes. Either the piston seal has excessive wear or the piston check ball located in the end of the shaft is clogged with debris.

  1. Disassemble pump and check for debris in piston check ball/seat or excessive wear on piston seal.
  2. Replace any worn/damaged parts.
  3. Clean and reassemble.
Last updated on April 2, 2018 BOSS Proportioner is losing fluid pressure #

Any holes in the hose will cause the proportioner to lose pressure. Inspect hose for leaks or damage.

Last updated on April 2, 2018 Fluid pressures are off-ratio #






    If the A-Side is High, follow these steps:

  1. Check A-Side inlet screen on gun. If clogged, clean or replace screen. If not, proceed to Step 2.
  2. Clean mixing chamber with proper clean-out drill bits. If fluid pressure is still off-ratio, proceed to Step 3.
  3. Replace A-Side non-heated whip hose, or if desired, check A-Side non-heated whip hose for obstruction. If these steps don’t resolve the problem, there could be an air pocket in the A-Side pump usually caused by the barrel pump sucking air. Proceed to step 4.
  4. Turn off pressure the toggle switch on face of machine and use barrel pump to circulate 100 strokes through the gun block and back into the A-Side drum. This will move the air pocket out of the pump.

If the B-Side is High, follow the exact same steps as the above process for A-Side.

Last updated on April 2, 2018

13.2.2.Fluid Pump Issues and Problems #

Use the section below to troubleshoot any Fluid Pump issues.

Last updated on April 2, 2018 A-Side pump is leaking around shaft #

Solution: The high pressure seal needs to be replaced.

There are two versions of the fluid cup assembly.

Pumps manufactured after 1/1/17 have tightening holes in the fluid cup assembly.
All pumps assembled before 1/1/17 do not have holes.

If the BOSS Proportioner contains the old style solvent cup, replace with a high pressure lip seal by following these steps:

  1. Unscrew and remove the four bolts that hold the solvent cup and pump to the mid-plate.
  2. Drop pump down and remove solvent cup from the top of the pump. This may require a screwdriver to pry the solvent cup loose from the pump head.
  3. Pull solvent cup completely off the shaft and rebuild.

If the BOSS Proportioner contains the new style solvent cup, replace with a chevron packing and follow the above-mentioned steps. When replacing the chevron packing, the packing nut should be snug but not too tight, as it is possible to tighten the nut to the point of locking the pump up. Loosen the packing nut, then screw it back in until the nut contacts the seal, tighten the nut approximately 1/8 turn, until snug.

For both old and new style solvent cups, monitor pumps to make sure there is no excess material weeping out of the top of the pump. Tighten the packing nut in very small increments as needed to help stop any excess material that is coming past the top seal.

Last updated on April 2, 2018

13.2.3.Troubleshooting Hose Heat Issues #




CAUTION! All electrical testing must be done by a qualified electrician.


Step 1: Checking the Controller

Set the Hose Heat Controller to a temperature that will ensure the system will be calling for hose heat. Once this is done, check to see if the green light in the upper left corner of the Hose Heat Controller is blinking (see image below-red circle).


If the light is blinking, it indicates the controller is functioning properly by calling for hose heat. Proceed to Step 2.  If the light is not blinking, there is likely a problem with the controller. Check all inputs into the back of the Hose Heat Controller to make sure everything is secure. If the problem persists, the Hose Heat Controller may be damaged and require replacement. This can be validated by swapping one of the other controllers (either of the material heat controllers) with the Hose Heat Controller. If the green light begins to flash, check to see if the hose is heating. If you have hose heat, simply replace the defective controller with a new, programmed temperature controller. If there is still no hose heat, proceed to Step 2.

Step 2: Checking the Electrical System

Set a voltage meter to 600V. With the system running and calling for hose heat, check the hose electrical system. Using the voltage meter, pierce the insulation with the black probe on one of the two red hose heat wires that extends out from the front of the proportioner. Next, place the red probe in the other red hose heater wire. With both probes in place, read the volts displayed on the meter. The expected result is 64 volts +/-.

If volts are displayed on the meter but there is no hose heat at all: The red hose heat wires within the hose segment have become disconnected or damaged. The most common reason is that the wire became disconnected at a wire coupler as shown in the pic below. The most common area of disconnections are:

  • Where the red wires coming out of the front of the reactor connect to the same wires on the hose.
  • Between the 200 ft. of hose and the 10-ft. whip hose

If volts are displayed on your meter when the Hose Heat Controller is calling for hose heat (green light flashing in upper left corner of controller), there is an electrical issue within the proportioner that needs to be identified and resolved. These are the two most common places issues are found:

  • Hose Heater Fuse-Fuse is in the base of the proportioner on the left side (see pic below/left-green circle). The fuse is a safeguard that connects the black power wire from the transformer to the red hose heat wire that is one of the two hose heat wires that extend from the front of the proportioner. This connection and fuse can be checked without rig power by performing a simple continuity test using your electrical meter. Set the meter to the continuity setting and place a probe against the wire on each side of the fuse (black wire and red wire.) If there is continuity, the meter will beep. This indicated power can flow through this area. The fuse is blown and needs to be replaced.

  • Hose Heater Relay-Located in the base of the proportioner on the left side (yellow circle above.) This relay is like a switch that is flipped by the Hose Heat Controller when the actual hose temperature is lower than the set hose temperature. The next step is to validate the relay is doing its job.

Confirm that all wires are secured to the four terminal posts located on each corner of the relay. There are two smaller input wires and two larger output (load) wires that come from the Hose Heat Controller. One of these wires is a black “0 Volt” wire from the Transformer and the other is Red wire that extends out of the front of the proportioner.

If all wires are securely connected, the next step is to do a continuity test between the two output or load wires. This test MUST be performed when the system is on and the Hose Heat Controller is calling for heat (flashing green light). To do this, set the electrical meter to the continuity setting and carefully place one probe on each output or load post. If no continuity exists, the controller needs to be replaced.

Hose warms up but doesn’t reach the target temperature

Step 1: Checking the Controller

Make sure the target temperature is set correctly at the controller.

Step 2: Check Amperage on Hose Heat Wires

  • First, ensure the system is set to call for hose heat.
  • Second, set your meter to the AC amperage test mode, 200A~ or ACA 200     depending on the meter and position it around one of the two red hose heat wires coming out of the front of the proportioner and then close the clamp. Record the amp reading and then follow the same procedure for the other red hose heat wire. Both readings should be very close to each other and between 35 and 45 amps. If the readings are lower than that but greater than zero:
    • Shut down the power to the proportioner.
    • Remove the black Transformer Lead Wire from the fuse connector (see pic on right below).
    • Note the voltage on the white tag of the removed lead wire.
    • Cover the exposed wire on the removed lead with a wire nut and secure with electrical tape.
  • Select the next larger lead wire by checking the white tag on the other lead wires in the “ponytail” of wires coming from the Transformer.
  • Install the new lead wire in the fuse connector.
  • Repeat step two to determine the amperage of the two red hose heat wires. If it is between 35 and 45 amps, see if your hose heat issues have been resolved.

PROBLEM: Hose is too hot

Step 1: Checking the Controller

Confirm the target temperature is set appropriately on the Hose Heat Controller.

  • If the actual hose temperature on the Hose Heat Controller is higher than the set temperature AND the green light in the upper left corner of the controller is flashing, your controller needs to be replaced with a new, programmed controller.
  • If the actual hose temperature reported on the controller is higher than the set temperature AND the green is not flashing in the upper left corner of the Hose Heat Controller, your Hose Heat Relay needs to be replaced.
  • If the actual hose temperature reported on the controller seems significantly lower than the hot hose, do the following:
    1. Remove power from the system.
    2. Make sure all the wires on the input side of the Hose Heat Relay are secure.
    3. If you repaired any unsecured wires in the previous steps, restart the system to determine if the issue was resolved. If not, continue to the next step.
    4. Disconnect the wire nuts that connect the purple Temperature Sensing Unit (TSU) wire from the proportioner to the hose.
    5. Using the purple TSU wire on the proportioner, twist the purple and red wires together (set aside the silver, uninsulated braided wire.) To be clear, the purple TSU wire contains three wires under its purple, insulating sleeve.
    6. Apply heat to the two twisted wires and watch the Hose Heat Controller temperature display. If the displayed temperature does not increase as heat is applied, your hose heat controller will probably need to be replaced with a new, programmed controller. If the displayed temperature increases as heat is applied to the twisted TSU wires, the issue resides with the TSU wire somewhere down the hose. The usual cause is the exposed sensor wires at the end of the TSU being pulled out and away from the heated hose. This prevents the TSU from reading the actual hose temperature which typically results in the ambient temperature being sent to the Hose Heat Controller which in turn causes the controller to continue to call for hose heat.

Last updated on April 2, 2018

13.2.4.Troubleshooting Preheater Issues #



WARNING! Before troubleshooting make sure the Main Power Switch is OFF. NEVER access the inside of the Control Panel with the Proportioner power supply ON. The Heaters are components that reach high temperatures; you must wait until they cool before handling.

WARNING! Before proceeding with any troubleshooting that requires power up of unit, ensure all testing is performed by a qualified electrician.

NOTE! The Thermal Limit Switch is a safety switch in contact with the Heater body. If the surface temperature exceeds 180F (82C) the Limit Switch will shut off the Heater power.

Insert preheater line drawing here with applicable warning signs.




  1. Shut off all electricity.
  2. Take off front cover of preheater.
  3. Press “red” button in on thermal limit switch.
  4. Replace front cover of preheater.
  5. Turn electricity ON.
Last updated on April 2, 2018

13.2.5.Troubleshooting Reversing System Issues #


    Check the following:

  1. Put 5-10 drops of pneumatic oil into the airline between the air regulator and the air distribution valve. This will lube the o-rings inside the air directional valve.
  2. If you have a machine older than 2016, then you may want to replace the exhaust muffler with the new style exhaust mufflers. The older style tends to clog up after many years and slow down the performance of the machine.




Identify the following three components:

  1. Air Distribution Valve:
    The air distribution valve is located directly on the back of the electric console of the proportioner.  You can identify it by one red air hose coming into the bottom of it and two red air hoses coming out the top that lead to the lower and upper plates of the air motor plates.
  2. Coil:
    There are two coils the need to be working in order for the reciprocation of theair motor to work. These coils can be identified by looking on each end of the air distribution valve. There is one coil on the left and one on the right. They each have a wire coming out of them that leads into the electric console. These             magnets pull a pilot valve their direction which in turn determines the direction of the air flow going to the air motor. If air pressure goes into the bottom of the air motor it will force the piston up and if air pressure goes into the top of the air         motor it pushes the piston down. Usually only one of the coils will go out at a time which will result in the air motor stopping in either the up or down position, depending on which coil goes out.
  3. Magnetic Proximity Switches/Reversing Switches:
    To identify these blue magnetic reversing switches, look between the air motor and the fluid pumps. These two switches are blue with a small wire coming out of them going to the electric console. They are mounted on swing brackets that are attached to the round upright bars that separate the two mid-plates.  

Once these three components are identified, test each to determine which is not working correctly. Before testing the machine, make sure that air pressure, electricity feeding to the machine, and all breakers are turned on. Perform the tests in the following order:

  1. Test 1 (Air Directional Valve):
    To test the air directional valve, locate the two flat screws located on the top of the air directional valve. These should be in the 0 position. If one or both are in the 1 position, then turn it back to 0. These flat screws are located on the top of the air valve just inside of the coil, on the body of the air valve.  Turn one at a time from the 0 position to the 1 position. This should make the proportioner cycle one time, either up or down depending on which screw is turned. Turn the screw back to the 0 position. If the air motor didn’t cycle, then the air directional valve is not functioning correctly.  The air directional valve will need to be replaced. If it is functioning correctly, turn the other flat screw to the 1 position. The air motor will cycle in the opposite direction. If it does not, the air directional valve is not functioning correctly and needs to be replaced. If the air directional valve strokes in both directions with the turn of the flat switches, then your air directional valve is functioning correctly. Proceed to test 2.

  2. Test 2 (Reversing Switches):
    Disconnect the wires that go to the switch from inside the electric panel. Remember to turn off all electricity feeding the electric console before opening the lid. Disconnect the end of the two wires from the termination block inside the machine and test them for continuity. To test, place a screwdriver in front of the reversing switch that needs to be tested. If the switch is working properly, then it will test for continuity when there is metal in front of the switch. If there’s no continuity when the screwdriver is directly in front of the blue reversing switch then the switch is not functioning correctly and needs to be replaced. Perform this same test on each switch to see if they are functioning correctly. If switches are functioning correctly, proceed to test 3.
  3. Test 3 (Coil):
    If both the air directional valve and the blue magnetic switches are working properly, the problem is most likely a coil.  Knowing that both coils don’t usually go bad at the same time, assume that one of them is still working. Take both coils off and replace the left side coil with the right coil. It will make the air motor cycle one time. If not, then the coil is bad. Now repeat with the right side coil and put it on the left side. It will make the machine cycle one time.  If not, then that coil is not functioning correctly, it will need to be replaced.


Current Wiring Diagram

Previous Wiring Diagram

Last updated on April 2, 2018

14.Technical Data #

Last updated on April 2, 2018

15.Spray Foam Equipment Standard Warranty #

Spray Foam Equipment warrants all equipment referenced in this document which is manufactured by Spray Foam Equipment and bearing its name to be free from defects in material and workmanship on the date of sale to the original purchaser for use. With the exception of any special, extended, or limited warranty published by Spray Foam Equipment, Spray Foam Equipment will, for a period of twelve months from the date of sale, repair or replace any part of the equipment determined by Spray Foam Equipment to be defective. This warranty applies only when the equipment is installed, operated and maintained in accordance with Spray Foam Equipment’s written recommendations.

This warranty does not cover, and Spray Foam Equipment shall not be liable for general wear and tear, or any malfunction, damage or wear caused by faulty installation, misapplication, abrasion, corrosion, inadequate or improper maintenance, negligence, accident, tampering, or substitution of non-Spray Foam Equipment component parts. Nor shall Spray Foam Equipment be liable for malfunction, damage or wear caused by the incompatibility of Spray Foam Equipment with structures, accessories, equipment or materials not supplied by Spray Foam Equipment, or the improper design, manufacture, installation, operation or maintenance of structures, accessories, equipment or materials not supplied by Spray Foam Equipment.

This warranty is conditioned upon the prepaid return of the equipment claimed to be defective to Spray Foam Equipment for verification of the claimed defect.  If the claimed defect is verified, Spray Foam Equipment will repair or replace free of charge any defective parts. The equipment will be returned to the original purchaser transportation prepaid.  If the inspection of the equipment does not disclose any defect in material or workmanship, repairs will be made at a reasonable charge, which charges may include the costs of parts, labor, and transportation.


Spray Foam Equipment’s sole obligation and buyer’s sole remedy for any breach of warranty shall be as set forth above. The buyer agrees that no other remedy (including, but not limited to, incidental or consequential damages for lost profits, lost sales, injury to person or property, or any other incidental or consequential loss) shall be available.


These items sold, but not manufactured by Spray Foam Equipment (such as electric motors, switches, hose, etc.), are subject to the warranty, if any, of their manufacturer. Spray Foam Equipment will provide purchaser with reasonable assistance in making any claim for breach of these warranties.

In no event will Spray Foam Equipment be liable for indirect, incidental, special or consequential damages resulting from Spray Foam Equipment supplying equipment hereunder, or the furnishing, performance, or use of any products or other goods sold hereto, whether due to a breach of contract, breach of warranty, the negligence of Spray Foam Equipment, or otherwise.

Spray Foam Equipment Information

For more information, visit our website or contact
our Spray Foam Equipment Headquarters:
(318) 644-5140

Spray Foam Equipment
1705 Beulah Church Rd.
Calhoun, LA 71225

Last updated on April 2, 2018
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