Installing the 125-5468 Heater Kit on 3412 Generator Sets{1050, 1350} Caterpillar

Introduction

The new 125-5468 Heater Kit (Fuel Fired Jacket Water Heater) is now available to help engine starting in cold weather. This jacket water heater should be used whenever the ambient temperature is less than 20°C (68°F). When ambient temperatures drop below 20°C (68°F) the generator set can be hard to start and may produce unwanted white smoke until it warms up to normal operating temperatures. Installing this heater kit will help to eliminate hard engine starting and unsatisfactory white smoke.

This unit is an electronically controlled, diesel fuel fired heater that operates on existing fuel and the generator set batteries. It heats the engine coolant and circulates it with an electric pump.

The heater is installed on the base of the generator set and is fueled by diesel fuel from the generator fuel supply line. It is an excellent choice for locations where electricity for the 7E-6248 Electric Jacket Water Heaters is not available.

The 125-5468 Heater Kit is available for field retrofits or can be installed as an attachment on new generator sets.

All the necessary parts for installing the heater are in the kit. They include, a microprocessor controller, controller enclosure, mounting brackets, fuel line, exhaust pipe, valves, hoses, cables, bolts, washers, screws, clamps, and burner assembly.

Do not perform any procedure, outlined in this publication, or order any parts until you have read and understood the information contained within this Special Instruction.

Features of the Heater Kit

The system is designed to provide the engine with a coolant water temperature of 57 to 85°C (135 to 185°F) for easy, warm starting. By keeping the coolant water warm, it will indirectly warm the oil in the oil galleys and wear surfaces. Warm starting also reduces down-time due to cold start situations, and is designed for long-term operation with only minimal routine maintenance.

The 125-5468 Heater Kit is designed with a unique self-diagnostic feature, which allows the electronic controller to display possible problems and indicate where a problem exists.

The system uses a high temperature limit switch that will automatically shut down the heater in case of heater failure or if the batteries reach critical cranking voltage.

Specifications

Parts Ordering

The parts listed in the chart below, must be supplied by the customer. All these parts can be ordered through Caterpillar dealers. The parts listed in Chart B are all included in the kit.

All parts without Caterpillar part numbers, listed in the parts charts, can be ordered from:

Nomenclature For Heater Kit Parts
(Refer to Chart B for item identification.)

Serviceable Parts

Burner Assembly Parts

Burner Head Assembly Nomenclature

Installation Section

Mounting the Heater Unit and Control Box to the Generator Set

Install Mounting Plate (2) Using Original Bolts (1)
(A) Right side of generator as viewed from rear of engine.

1. Remove two nuts, bolts, and washers (1) and install plates (2) as shown.

Mount Heater Unit To Mounting Plate
(2) Mounting plate. (3) 4B-5273 Washer. (4) Mounting washer. (5) 3B-4504 Lock Washer. (6) 6V-8185 Nut.

2. Mount the heater unit onto mounting plates (2) using two washers (3), washer (4), lock washer (5), and nut (6) as shown. Tighten the nut to standard torque.

Mount Control Box (7) To Generator Enclosure (8)

3. Mount control box (7) to generator terminal box enclosure (8) in the general location shown.

a. Locate the control box to provide adequate clearance below the top cover of the terminal box enclosure. Also locate the box where the mounting screws will not interfere with any wiring or components inside the enclosure.

b. Mark the location of the four bolt holes using the control box as a guide.

c. Drill four mounting holes for the 10-24 screws. Make sure the drill does not hit any wiring or components inside the enclosure.

d. Clean up any metal shavings or chips. Do not allow any metal shavings to get into the generator.

e. Mount the control box using customer supplied hardware.

4. Secure the electrical cable leading from the heater unit to the control box using tie wraps.

Electrical, Fuel, and Water Connections

Make all necessary water, fuel, and electrical connections using the following procedures. After all the connections have been made, check the water and fuel lines for leaks. Secure all lines and hoses onto the generator set using tie wraps to reduce the possibility of abrasion damage.

Show/hide table

After the unit is correctly installed and functioning, it should not be left unattended with the top cover removed. Allowing the heater unit to function without the cover could lead to personal injury and/or severe burns due to the unit's high operating temperature.

Water Connections

1. Drain the coolant from the generator set engine. The coolant must be drained to a level below where the water connections to the heater unit are made.

Heater Unit Inlet (1) And Outlet (2)

2. Select the longest length of hose to connect water inlet (1) of the heater unit to the water outlet on the engine.

Connect Water Outlet On Engine To Water Inlet On Heater Unit (Left Side Of Engine As Viewed From Rear)
(3) 3/4-14 NPTF plug for water outlet. (4) Coolant fitting--3/4 Straight × 3/4 NPTF. (5) Coolant valve. (6) Hose fitting--3/4 hose barb × 3/4 NPTF. (7) Hose clamp--1 1/4 in, Size 12. (8) Coolant Hose--19.0 mm ID × 28.0 OD mm (.75 × 1.10 in).

3. Remove plug (3) and install pipe fitting (4), coolant valve (5), and hose fitting (6) into the water outlet port of the engine. Put 5P-3413 Pipe Sealant, or equivalent, on threads of fittings (4) and (6).

NOTE: The six bolt cover (6N-1782) [with plug (3)] may not be installed on all engines. In some cases a 4N-1682 Cover will be installed and does not have the threaded hole required to attach the water outlet hose. Either rework the 4N-1682 by drilling and tapping it with a 3/4-14 NPTF hole or replace the cover with a 6N-1682.

4. Connect hose (8) to hose fitting (6) using clamp (7).

5. Connect the other end of hose (8) to inlet (1) of the heater unit. Secure to inlet, using clamp (7).

Connect Water Inlet On Engine To Water Outlet On
Heater Unit (Right Side Of Engine As Viewed From Rear) (4) Coolant fitting--3/4 Straight × 3/4 NPTF. (5) Coolant valve. (6) Hose fitting--3/4 hose barb × 3/4 NPTF. (7) Hose clamp--1 1/4 in, Size 12. (8) Coolant Hose--19.0 mm ID × 28.0 OD mm (.75 × 1.10 in). (9) Plug for water inlet.

6. Select the remaining (shorter) length of hose to connect the water outlet of the heater to the water inlet of the engine on the oil cooler.

7. Remove plug (9) from the oil cooler and install pipe fitting (4), coolant valve (5), and hose fitting (6) into the water inlet port of the engine. Install the 126-4255 Check Valve, if inlet and outlet pressures are different. Put 5P-3413 Pipe Sealant, or equivalent, on threads of fittings (4) and (6).

NOTE: The 126-4255 Check Valve (not part of this kit) keeps coolant from flowing backwards through the system. This check valve only needs to be installed if the outlet and inlet water pressures are different. The check valve does not need to be installed on 3412 Generator Set engines.

8. Connect hose (10) to hose fitting (6) using clamp (7).

9. Connect the other end of hose (10) to outlet (2) of the heater unit water pump. Secure to outlet using clamp (7).

Fuel Connections

1. Shut off fuel to the engine and drain fuel from inlet line (6).

Install Tee Fitting In Fuel Inlet Line And Connect Heater Unit's Fuel Line
(1) Fuel block. (2) Fuel return line port. (3) Fuel inlet line port. (4) Customer-supplied tee fitting. (5) Fuel fitting assembly. (6) Fuel inlet hose assembly. (7) Ferrule nut. (8) Fuel line, black.

2. Remove inlet hose assembly (6) from fuel block (1).

3. Install, customer-supplied, 6B-7639 Tee Fitting into fuel block inlet.

4. Connect fuel inlet line (6) to one end of tee fitting (4). Install fuel fitting assembly (5) into the side of the tee fitting.

5. Put a ferrule nut (7) onto the end of the fuel line and connect it to fuel fitting assembly (5). Put 5P-3413 Pipe Sealant, or equivalent, on threads of fittings.

Connect Black Fuel Line (8) To Heater Unit's Fuel Pump (7) Ferrule nut. (8) Fuel line. (9) Fuel pump.

6. Route the fuel line back to the heater unit as shown in the illustration (do not loop excess fuel line inside the heater enclosure). Put another ferrule nut (7) on the end of black fuel line (8) and connect it to heater unit's fuel pump.

7. Secure the fuel line in place using tie wraps.

Electrical Connections

1. Route the electrical cable to the battery and secure the electrical cable in place using tie wraps.

Connect Electrical Cable Ring Terminals To Battery (B+) And Ground (B-)
(1) Ring terminals on red wires (B+). (2) Ring terminals on black wires (B-).

2. Connect two ring terminals (1), red wires, to the positive (B+) side of the battery. The connection can be made using the bolt that clamps the battery terminal onto the post.

3. Connect two ring terminals (2), black wires, to any convenient ground (B-) location or battery negative.

Exhaust Tube

Connect the flexible exhaust tube to the heater unit using the clamp provided with the kit. If desired, the exhaust tube can be routed under the frame of the generator set. Wherever the exhaust is routed, it must meet local and state codes.

Show/hide table

The exhaust from the heater unit is hot enough to cause burns. Route the exhaust away from potential contact with the operator or combustible material.

Final Preparation

Check Coolant Levels

The heater kit should now be completely installed. Before starting the engine, fill the cooling system with coolant and purge all air from the system by releasing it at the heater core outlet connection. Check the coolant level again and add coolant as required. Make sure all coolant flow valves and heater controls are in their full open position before starting the system.

Refer to the instructions for programming and operating the controller.

Fuel Pump Priming

The fuel pump is self-priming, but may require more than one start cycle to be completely primed. If it does not prime and start on the first cycle, refer to the Operation Section to reset and restart the system. If the system does not prime and start on the second attempt, check all fuel line connections for tightness. Restart system again.

Operation Section

Safety

Do not perform any procedure, outlined in this publication, or order any parts until you have read and understood the information contained within this Special Instruction.

Show/hide table

Always shut off the system when refueling the generator set. This helps prevent potential fire hazard and personal injury caused by fuel contacting hot exhaust components. Do not operate this system inside a closed building. Lack of proper ventilation can cause possible asphyxiation or carbon monoxide poisoning resulting in injury or death.

System Description

The electronic controller can be manually turned ON or OFF, programmed to turn ON automatically based on time, or programmed for automatic operation according to engine coolant temperature.

The 125-5468 Heater Kit can be operated in one of three modes: ON/OFF, Auto ON, and Auto OFF.

The ON/OFF mode allows manual operation of the system. When the ON/OFF key is pressed, the system will run indefinitely until the system is turned OFF or a problem in the system occurs.

The Auto ON mode is used to automatically activate the system by the preprogrammed time or temperature settings. The "auto time" will activate the system to run for the duration of the "RUN TIME" setting which can be programmed from one to nine hours. The "auto temp" will start the system when the preprogrammed temperature setting is reached. The system will maintain the programmed temperature until the Auto key is manually deactivated.

The Auto OFF mode will allow the system to operate for the duration of the RUN TIME and then automatically shut the system OFF. This mode works only when the ON/OFF and AUTO keys have been activated.

Two Basic Components Of The 125-5468 Heater Kit
(1) Heater unit. (2) Electronic controller.

The heater kit consists of two basic components. A heater unit (1) is controlled by an electronic controller (2). The electronic controller operates the heater unit based on time (manually or automatically started) or the temperature of the engine coolant.

Start Cycle

The electronic controller is used to activate or turn ON the system. Once activated, this system uses the water temperature in the engine to determine when the unit should start heating the coolant. If the coolant temperature is below 57°C (135°F), the heater unit will activate (start its combustion process) and raise the coolant temperature. If the temperature is above 57°C (135°F), the water pump will be turned ON and the water in the cooling system will be circulated.

The following steps describe the events which take place during the start cycle.

1. The glow plug pre-heats for 25 seconds.

2. The combustion air fan in the heater unit starts.

3. The fuel pump starts pumping fuel two seconds after the combustion fan is turned on.

4. Fuel is delivered to the hot glow plug in the combustion chamber.

NOTE: During the first 60 seconds of operation, the fuel pump cycles ON and OFF. This can be heard by an audible clicking sound.

5. After 60 seconds and/or during continuous operation, the fuel pump runs at a constant four cycles per second.

6. Power to the glow plug is turned OFF when the flame check sensor detects a stable flame.

NOTE: If the flame check sensor does not detect a stable flame, the system will automatically attempt a second start cycle.

7. During continuous operation, the combustion air fan and fuel pump should run continuously.

Sequence of Operation

Once the system has completed its start cycle it is in continuous operation. Coolant temperature will now be controlled by the heating unit and the water pump.

1. If the coolant temperature is below 32°C (90°F) the water pump is shut OFF. When the coolant temperature reaches 38°C (100°F) the water pump is turned ON to circulate the coolant.

2. When the temperature is below 57°C (135°F) the fuel pump directs fuel into the combustion chamber of the heater unit to heat the coolant. Once a temperature of 85°C (185°F) is reached, the fuel pump is turned OFF and a purge cycle begins.

3. The purge cycle is 2.5 minutes long, at which time the combustion air fan and the water pump continue to operate. This allows the combustion chamber to properly cool. If the unit is disconnected from the power at this time, the purge cycle will not be completed and an excessive build-up of heat will occur in the combustion chamber.

4. After the purge cycle is complete, the water pump will continue to operate until the coolant temperature drops below the restart temperature.

5. The system will continue to repeat this cycle until the unit is turned OFF.

Electronic Controller Display

During the purge cycle the controller display will show the letters "Pur". After the purge cycle is complete, the display will show the current time.

NOTE: The keys on the electronic controller are disabled during the purge cycle.

The system will also activate a purge cycle when the system detects a potential problem. The display will show a trouble code (refer to the section on "Trouble Codes" for additional information).

Programming Instructions

Electronic Controller Keys

Programming of the electronic controller is performed by pressing the Set key (1) and either of the two arrow keys (2) or (3).

Key Description For Electronic Controller
(1) Set key. (2) Left arrow key. (3) Right arrow key. (4) On/Off key. (5) Automatic operation key.

1. Pressing the Set key allows:

a. Access to program options.

b. Chooses the option selected.

c. Resets the controller after a trouble code.

2. Pressing the Left arrow key:

a. Goes through program options (reverse).

b. Adjusts clock time (reverse).

c. Adjusts temperature to a lower setting.

d. Sets the day of the week.

3. Pressing the Right arrow key:

a. Advances through program options (forward).

b. Adjusts clock time forward.

c. Adjusts temperature to a higher setting.

d. Sets the day of the week.

4. Pressing the ON-OFF key manually starts and stops the system.

5. Pressing the Auto key causes the system to start and stop automatically.

Initial Controller Programming

When power is first connected or reconnected, the controller must be set for the correct day, time, and temperature. When power is first applied, the controller will display all of the characters for two seconds and the red SET light will automatically illuminate - indicating the controller is in the program mode.

Set Temperature Units

1. Select the desired temperature unit.

a. The °F unit will be flashing at this time. If the Fahrenheit is the desired unit, press the set key.

b. If Centigrade is the desired unit of measure, press either the Right or Left arrow key to select °C.

c. Press the Set key to select Centigrade as the desired unit.

Set Day Of Week

2. Select the current day.

a. SUN (Sunday) will now be flashing. Press the Set key if this is the correct day.

b. Use the Left or Right arrow key to select the current day other than SUN (Sunday).

c. Press the Set key to activate the selected day.

Set Units Of Time

3. Select the units of time by selecting AM, PM, or 24hr. (24hr is a 24 hour time unit).

a. AM will now be flashing. Press the Set key if this is the correct time unit.

b. If not, use the arrow keys to select the correct time unit.

c. Press the Set key to select the time unit.

Set Hour

4. Select the correct hour.

a. The number "12" should now be flashing.

b. Use the arrow keys and select the correct hourly time.

c. Press the Set key to set the hour.

Set Minute

5. Select the current minute.

a. The number "00" should now be flashing.

b. Use the arrow keys and select the correct minute.

c. Press the Set key to set the minute.

Unit Is Now Programmed And Initial Controller
Programming Is Complete
(1) Red set light.

6. The red Set light (1) should now be OFF and the display should show the current programmed settings. The initial electronic controller programming is now complete.

Recalling Trouble Codes from Memory

To recall trouble codes from memory:

1. Press the Set key.

2. Press arrow key(s) until Trouble Code is displayed.

3. Press the Left or Right arrow key view the trouble codes.

Manual Operation

1. Press the ON/OFF key to activate the system. If the coolant temperature is above 57°C (135°F) combustion will not start and the water pump will run until the temperature is less than 57°C (135°F).

Manual Operation Indicated By Green "RUN" Light

2. The green light on the ON/OFF key and the word "Run" will be displayed. The system will run indefinitely until it is turned OFF or a problem occurs.

3. To turn the system OFF, press the ON/OFF key.

System Is Shutting Down Indicated by "Pur" Shown On Display

4. The display on the electronic controller will show the letters "Pur" indicating the system is in the purge cycle and is shutting down. The purge cycle is approximately 2.5 minutes and occurs each time the combustion cycle is stopped.

Automatic Operation

Automatic operation is controlled by either time or temperature. Follow the appropriate procedure to automatically activate the system.

Starting the heater unit by time would be used when a generator set needs to be started at a specific time of day or night (example: 5:00 AM ALL days). The heater kit can be programmed to activate and heat the engine coolant from one to nine hours (RUN TIME) prior to the generator starting.

NOTE: The system can also be programmed not to start on certain days. For example, if the unit does not need to run on Saturday and Sunday, do this on Friday: Reprogram the controller to start on Monday at the time desired, and activate the Auto key. On Monday, reprogram the controller for "ALL" days and activate the Auto key.

Starting the system by temperature would be used to maintain engine coolant at a temperature which allows, easy, warm starting of the engine. The temperature activation of the system is used when the exact time of generator set operation is not known. The system will run indefinitely in this mode, keeping the engine coolant at a constant preset temperature range. The system will run until the Auto key is pressed/deactivated.

Programming Automatic Start by Time

1. Press the Set key and choose the AUTO option, using the Left or Right arrow keys.

2. Press the Set key and select the TIME option.

3. Press the Set key and select the desired start day.

4. Press the Set key and select desired "ON" time (hour).

5. Press the Set key and select desired "ON" time (minute).

6. Press the Set key and the current time and day will be displayed.

7. Press the Auto key to activate the system. To stop the auto start function before, during, or after system activation, press the Auto key again.

NOTE: The system will perform a purge cycle if the program has already been initiated. The controller keys are disabled during the 2.5 minute purge cycle.

Programming Run Time

1. Press the Set key and use the Left or Right arrow keys, to select the RUN TIME mode.

2. Press the Set key and select the desired running time from one to nine hours.

3. Press the Set key and the programmed information is recorded into the controller.

Programming Auto Start by Temperature

1. Press the Set key and use the Left or Right arrow keys, to select AUTO.

2. Press the Set key and select TEMP.

3. Press the Set key and set the desired minimum temperature.

4. Press the Set key and the programmed information is recorded into the controller and the current time and day are displayed.

5. Press the Auto key to activate the system.

6. The system will now operate at the preset temperature.

7. To stop the automatic operation, press the Auto key.

NOTE: The system will perform a purge cycle if program has already initiated. The controller keys are disabled during the 2.5 minute cycle.

Resetting Trouble Codes

Press Set key and attempt a restart, if the cause of the trouble code was NOT a mechanical failure.

If the cause of failure is mechanical, or if the system operates improperly, the reset function will not operate and the red Set key light will remain illuminated. Refer to the Maintenance Section Troubleshooting Guide.

Some trouble codes can be reset and another attempt can be made to start the system. These trouble codes include the following.

1. Low voltage. The system can be operated in one-hour intervals, if necessary. It is advisable to charge the batteries before resetting the system.

2. Failed start attempt. Although the system may start, it is advisable to determine the cause of the loss of flame before making a restart attempt.

3. Loss of flame during operation. Although the system may start, it is advisable to determine the cause of the loss of flame before making a restart attempt.

4. High temperature cut-out. The system will only reset if the coolant temperature at the heating unit is below 77°C (170°F). Determine the cause of overheating before turning the system back ON.

If the system continues to have problems, refer to the "Troubleshooting Guide".

Maintenance Section

Preventive Maintenance

1. All hose clamps on coolant and fuel lines should be checked for tightness and wear. Adjust the tension or replace as necessary.

2. All fuel and coolant hoses should be checked for abrasion, cracking, and firmness. Replace those that are worn or questionable.

3. All wires and connections should be checked. Replace all worn wires. Properly fasten new wires to prevent wear. All electrical connections should be tight, and free of any corrosion, rust, or insulating compounds. Clean and tighten as necessary.

4. All four vibration mounts should be checked. Tighten or replace mounts as required.

5. Inspect the exhaust tube for wear, blockage, and routing. Remove any blockage. Replace tubing if badly worn, but do not exceed 3.5 m (12 ft) with 32.0 mm (1.25 in) tubing.

6. Test the glow plug for serviceability at least once a year (the procedure is outlined in this section). Replace as necessary.

Troubleshooting

Trouble Codes

The 125-5468 Heater Kit has a microprocessor-based control system, which is self-diagnostic. This helps the mechanic/operator in troubleshooting specific trouble codes. These codes state what type of failure has occurred and can be used in conjunction with this Special Instruction for fast and effective repair of the system. When a problem occurs the system is shut down, the red Set light is turned ON, and the word "RESET" is shown on the electronic controller display.

There are ten trouble codes used by the system.

Show/hide table

Trouble codes are generated by components and/or sensors within the system. Do not operate the system with a damaged component or sensor. Do not bypass any sensor to operate the system. Operating the system with damaged components or sensors may cause personal injury or fire.

Each time a failure occurs, the trouble code is shown on the electronic controller display. Correct the cause of the trouble code and reset the system by pressing the Set key. Once reset, the system can be put back into operation.

In addition to displaying the most recent trouble code, the last five trouble codes are stored in memory in the order in which they occurred. To recall the stored trouble codes use the following procedure.

1. Press the Set key (red light in the corner of the key should illuminate).

2. Use the arrow keys and select TROUBLE CODE.

3. Press the Set key and the display will show the most recent trouble code.

4. Use the arrow keys to move through the last five trouble codes.

5. Press the Set key to exit the trouble code display mode.

Fuses

There are three fuses in the system: Main power connection (2), controller power connection (1), and inside the enclosure (3).

Fuse (2) protects the main power supply wire and glow plug (30 Amp, 24 volts). Fuse (3) protects the fan motor, coolant pump, fuel pump, and flame sensor (7.5 Amp, 24 volts). Fuse (1) protects the controller (3 Amp, 24 volts).

Before replacing fuses, perform the following operations:

Fuse Location
(1) 3 Amp fuse. (2) 30 Amp fuse. (3) 7.5 Amp fuse.

1. Locate and repair the source of the overload.

2. Remove the blown fuse and replace it with one of the same rating.

Disconnecting and Reconnecting Power

Show/hide table

Before performing maintenance on any electrical component, power to the system must be properly disconnected. This will prevent accidental component activation and voltage spikes to the electronic controller, which could result in injury and/or component damage.

Fuse Location
(1) 3 Amp fuse. (2) 30 Amp fuse.

To completely isolate the system (disconnect), use the following procedure.

1. Remove 3 Amp fuse (1) from end of wiring harness.

2. Remove 30 Amp fuse (2) from end of wiring harness (near the battery).

To re-connect power to the system, use the following steps.

1. Replace 3 Amp fuse (1).

2. Replace 30 Amp fuse (2).

3. The red light on the Set key should be lit. Follow the steps in the "Initial Controller Programming" as described in this Special Instruction.

4. If red light is not ON, do the following:

a. Disconnect the control cable from the electronic controller.

b. Remove 3 Amp fuse (1).

c. Wait two minutes.

d. Replace fuse (1).

e. Check for a red light on the Set key.

f. If red light is ON, reconnect the control cable to controller and continue with "initial Programming Sequence" as described in this Special Instruction.

g. If red light is not ON, go back to Step 2.

Fuel Pump Calibration Verification

Calibrating the fuel pump requires activation of the system. Do not remove any of the fuses, or disconnect the chassis ground.

The fuel pump flow rate should be 10.0 ml (.34 liquid oz) per minute. If improper calibration is suspected, proceed with the following steps using a 126-4256 Fuel Pump Calibration Test Kit.

Unhook Wire Connections
(1) Glow plug connector (green). (2) Flame check sensor connector (black and brown). (3) Fan motor connector (blue and pink).

1. Disconnect the flame check sensor connector (2). The wires leading to the connector from the burner assembly are black and brown.

2. Disconnect the green glow plug connector (1).

3. Attach one end of the jumper wire (supplied with test kit) to the brown wire terminal of the flame check connector (brown and black wire).

NOTE: Do not attach the jumper wire to the brown wire of the connector (brown and black wire) going to the burner assembly.

4. Attach the other end of the jumper wire to chassis ground.

Remove Fuel Line (4) From Fuel Pump

5. Remove fuel line (4) from fuel pump outlet.

6. Attach fuel hose (supplied in kit) to fuel pump outlet, and secure with clamps provided.

7. Place the other end of fuel hose into a container.

8. Press the ON/OFF key on the controller. Wait for the fuel pump to start (approximately 25 seconds).

9. Allow the fuel pump to run for one minute, pumping fluid into the container.

10. With the fuel pump running, place the hose in a graduated cylinder and begin timing (use a stop watch or clock with a sweep-second hand). Continue to fill the graduated cylinder for exactly two minutes.

11. At the end of two minutes, place the fuel line into another container. Stop the fuel pump by pressing the ON/OFF key on the controller.

A Correctly Calibrated Fuel Pump Will Supply 20 ± 0.4 Milliliters Of Fuel In Two Minutes

12. If the pump is properly calibrated, the graduated cylinder will contain 20 ± 0.4 milliliters of fuel.

13. If the fuel pump is out of calibration, replace the pump, or adjust it following the instructions in the next section.

14. If the fuel pump is correctly calibrated, re-connect the electrical and fuel connections.

Fuel Pump Calibration Procedure

Once the flow rate of the fuel pump is determined, the output can be adjusted using the following procedure.

Adjusting Fuel Pump Output
(1) Adjustment nut. (2) Jam nut. (3) Star washer.

1. Loosen jam nut (2) just above star washer (3).

2. Turn 10 mm adjustment nut (1) counterclockwise to increase the flow volume or clockwise to decrease the flow volume.

NOTE: Adjustments should be made in fractions of a turn, 1/8th revolution or less.

3. After each adjustment, repeat the "Fuel Pump Calibration Verification" procedure.

Fuel Pump Replacement

1. Disconnect power from the unit, as described in the "Disconnecting and Reconnecting Power" section.

2. Shut OFF the fuel supply to the system.

3. Disconnect the electrical connector to the fuel pump.

4. Remove both the inlet and outlet fuel hoses.

5. Loosen the band clamp holding the fuel pump to the enclosure and remove the fuel pump.

6. Install a new fuel pump in the reverse order.

7. Clean up any spilled fuel before reconnecting the electrical connectors.

NOTE: Before putting the system into service, make sure the fuel pump is correctly primed. Refer to the "Fuel Pump Priming" section.

Coolant Pump Replacement

1. Disconnect the electrical connector from the water pump.

2. Drain coolant, close shut-off valves, or clamp off coolant hoses.

3. Remove coolant inlet hose from coolant pump.

4. Remove the hose connecting the coolant pump to the heater body.

5. Install a new pump in reverse order.

6. Check coolant level and fill as required.

Glow Plug and Flame Check Sensor Replacement

1. Disconnect power from the unit, as described in the "Disconnecting and Reconnecting Power" section.

Disconnect Wire Connections
(1) Glow plug connector. (2) Flame check sensor connector. (3) Fan motor connector.

2. Disconnect the glow plug connector (1). The connector wire is green.

3. Disconnect the fan motor connector (3). The connector wires are pink and blue.

4. Disconnect the flame check sensor connector (2). The connector wires are black and brown.

Remove Fuel Line (4) From Fuel Pump

5. Unhook and remove fuel line (4) from the burner assembly.

Remove Glow Plug Or Flame Check Sensor
(5) Air hood and fan motor assembly. (6) Burner assembly. (7) Tube. (8) Glow plug wire. (9) Fuel tube. (10) Glow plug. (11) Flame Check Sensor.

6. Remove two socket head capscrews holding air hood and fan motor assembly (5) onto burner assembly (6).

7. Remove air hood and fan motor assembly (5) and tube (7). It may be necessary to remove the clamps holding the burner assembly and rotate it upward and to the front of the enclosure to remove the parts (5) and (7).

8. Disconnect green wire (8) from glow plug (spade-type connection).

9. Remove fuel tube (9), glow plug (10), and/or flame check sensor (11). Replace as necessary.

10. Reassemble the unit in reverse order.

11. Reconnect power to the unit.

Combustion Air Assembly Removal

1. Disconnect power from the unit, as described in the "Disconnecting and Reconnecting Power" section.

Remove Air Hood And Fan Motor Assembly
(1) Fan motor connector. (2) Fan motor mounting housing. (3) Burner assembly. (4) Tube.

2. Disconnect fan motor connector (1). The connector wires are red and blue.

3. Remove two socket head capscrews holding air hood and fan assembly (2) onto burner assembly (3).

4. Remove air hood and fan motor assembly (2). A small rubber grommet which the wires pass through, must be removed from tube (4).

5. Reassemble the unit, and reconnect the power to the system.

Burner Head Assembly and Heater Body Replacement

1. Disconnect power from the unit, as described in the "Disconnecting and Reconnecting Power" section.

2. Drain coolant, close shut-off valves, or clamp coolant hoses.

3. Disconnect all electrical connections from the heater body (glow plug, frame check sensor, fan motor, coolant sensor, and high temperature switch). Also, uncouple the connector for the water pump.

Remove Burner Assembly From Unit
(1) Fuel hose. (2) Outlet hose. (3) Inlet hose. (4) Band clamp.

4. Remove fuel line (1) at heater body.

5. Remove coolant outlet hose (2) from the top of the heater body and coolant inlet hose (3) from water pump. The water pump remains attached to the heater body.

6. Remove exhaust tube from the heater body.

7. Remove both band clamps (4) holding heater body to enclosure, and the band clamp holding the water pump to the enclosure.

8. Remove heater body with water pump attached.

9. Remove two socket head capscrews holding air hood and fan motor assembly (5) onto burner assembly (6).

Remove Burner
(5) Air hood and fan motor assembly. (6) Burner assembly. (7) Tube. (8) Glow plug connector. (9) Burner head assembly.

10. Remove air hood and fan motor assembly (5) and tube (7).

11. Disconnect green wire (8) from glow plug (spade-type connection).

12. Remove burner head assembly (9).

13. Remove fuel line, glow plug, and flame check sensor. This step is only required when the burner head assembly is replaced.

14. Clean and inspect the heater body for internal damage. Replace the heater body, if necessary.

15. Reassemble the unit in reverse order and reconnect power to the system.

Controller Wiring Diagram

System Wiring Diagram