TM 10-4610-232-34
Table 2-1. Direct Support Troubleshooting Guide (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
2. Flowmeter is inaccurate, flowmeter needs adjustment.
Step 1. Shut down the ROWPU and open the control panel. Remove the access panels from the back of the
flowmeters. Restart the ROWPU.
Adjust the feed flowmeter to read 102 GPM by turning the adjustable pot located in the flowmeter
access panel. Turn it clockwise to increase the reading and counterclockwise to lower it (para. 2-23).
Step 2. Attach the auxiliary flowmeter to the product out hose and read the flow.
Adjust the product flowmeter to the correct reading (para. 2-23).
Step 3. Subtract the product flow rate from the feed flow rate to obtain the waste rate.
Adjust the waste flowmeter (para. 2-23).
DIESEL FUEL HEATER.
(Refer to Figure 2-2.)
1. Fan fails to go to high speed during burning cycle.
Use a condenser tester and check for a faulty capacitor Capacitors are rated at 0.68 mfd.
(a) Replace if faulty (para. 2-54).
(b) Replace motor. Refer to para. 2-54.
2. Heater fails to start (motor fails to run).
Use a condenser tester and check for a faulty capacitor. Capacitors are rated at 0.68 mfd.
(a) Replace if faulty (para. 2-54).
(b) Replace motor. Refer to para. 2-54.
3. Heater has excessive backfiring or popping.
Step 1. Check carburetor.
Disassemble, clean and repair as necessary (para. 2-54).
Step 2. Check solenoid valves.
Disassemble, clean and repair as necessary (para. 2-54).
Step 3. Check mixer housing.
Disassemble, clean and repair as necessary (para. 2-54).
4. Heater remains on burner cycle after heat demands are met.
Step 1. Check the hold-fire thermostat assembly and the temperature control switch for operation. Check the
temperature control switch for sticking.
Disassemble, clean and repair as necessary (para. 2-54).
Step 2. Check the primary fuel solenoid.
Disassemble, clean and repair as necessary (para. 2-54).
5. Heater shuts down when heat demands are met and needs to be restarted. Does not stay on low-fire until heat
is required.
Check the hold-fire thermostat assembly and the temperature control switch for operation and for sticking.
Disassemble, clean and repair as necessary (para. 2-54).
6. Heater leaks fuel.
Isolate the fuel leak.
Refer to para. 2-54 and disassemble the leaking component. Replace gaskets as required.
7. Heater leaking fumes into ROWPU van.
Check the heat exchanger.
Remove and inspect the heat exchanger thoroughly for cracks, holes, broken weldments and other
damage. If damaged, replace it. Do not attempt repair. Always use new gaskets and exhaust connector
when installing heat exchanger (para. 2-54).
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