TM 5-4520-256-14
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
If continuity check indicates an open circuit, replace the transformer.
If continuity check indicates continuity, proceed to step 7.
Step 7.
Check for damaged high tension cables (para 3-30).
If the cables are damaged, repair or replace and proceed to step 8.
Step 8.
Inspect burner electrodes and adjust for proper gap (para 3-38).
If electrodes are damaged, replace them.
If electrodes are out of adjustment, adjust electrodes.
9.
THERMOSTATS DO NOT CONTROL THE BURNER OR SHELTER TEMPERATURE.
Step 1.
Perform the steps of MALFUNCTION 7.
If the problem still exists, proceed to step 2.
Step 2.
Remove and tag the wire leads on terminals 7 and 8 of the temperature controller. The leads are 28
Vac signal lines. Proceed to step 3.
Step 3.
Connect the two wires removed in step 2 together. Proceed to step 4.
Step 4.
Set OFF/VENT/HEAT switch (S1) to HEAT mode. The burner should be firing.
If the burner fires, proceed to step 5.
If the burner does not fire, replace safety relay (para 3-17).
Step 5.
Set OFF/VENT/HEAT switch (S1) to OFF, disconnect the wires connected in step 3 and tape over
the ends. With the ends disconnected set OFF/VENT/HEAT switch (S1) to HEAT mode. The burner
should not fire.
If the burner does not fire, proceed to step 6.
If the burner fires, replace the safety relay (para 3-17).
Step 6.
Set OFF/VENT/HEAT switch (S1) to OFF and connect the two wires removed in step 2 to terminals 7
and 8 of the temperature controller. Proceed to step 7.
3-13
