Table 2-2. Unit Troubleshooting (Continued)
TEST OR INSPECTION
WATER HEATER FAILS TO START. (Cont)
Check low water probe for loose or corroded connection, broken insulator, or shorted circuit.
Check for water leaks around base of water probe.
Clean or replace probe as needed.
If probe is not defective, proceed to next step.
Check for defective low water relay. With power off, measure a low resistance between terminals
1 and 2. Make a similar measurement between terminals 9 and 10 on low water relay.
If either measurement is open, notify your supervisor.
If continuity is indicated on both measurements and problem persists, notify your super-
WATER HEATER FLAME FAILS DURING FIRING CYCLE.
Check for low fuel supply in fuel container.
If container is low on fuel, fill container with fuel.
If container fuel level is correct, proceed to next step.
Check for leaks in fuel hoses.
If fuel hoses are leaking, tighten couplings or replace fuel hoses.
If fuel hoses are not leaking and couplings are tight, proceed to next step.
Check for clogged fuel hose.
If fuel hoses are clogged, disconnect fuel hose and clear foreign matter and clogs from
If fuel hoses are clear, proceed to next step.
Check for dirt and clogs in fuel nozzle.
If fuel lines are clogged or dirty, clean or replace nozzle. Refer to paragraph 2-36.
If nozzle is clean, proceed to next step.
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