TM 10-4520-259-13&P
Table 4-2. Unit Troubleshooting Procedure
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
1.
WATER HEATER FAILS TO START
Step 1.
Check low water probe for defects.
Notify direct support maintenance if it is defective.
Step 2.
Check low water relay for defects.
Notify direct support maintenance if it is defective.
2.
FLAME FAILURE DURING FIRING CYCLE.
Step 1.
Check fuel nozzle for dirt and clogs.
Clean or replace nozzle.
CAUTION
The scanner is a sensitive device. Rough handling can damage the scanner and
result in possible failure of the flame safeguard control.
Step 2.
Check UV scanner tube to see if it is clogged.
Clear obstructions from UV scanner tube.
Step 3.
Check operation of flame safeguard control to see if it is defective.
Notify direct support maintenance if defect is noted.
Step 4.
Check UV scanner for defects.
Notify direct support maintenance if defect is found.
Step 5.
Inspect fuel pump strainer to see if it is clogged.
Remove and clean strainer.
Step 6.
Check fuel pump drive coupling for looseness.
Tighten fuel pump drive coupling.
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