TM 5-4520-256-14
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 5.
Check for 120( ± 10) Vac at terminal 7 of OFF/VENT/HEAT switch (S1) and TB1, terminal 3.
If voltage is present (indicating open motor windings), notify Direct Support Maintenance.
For model H83 only: If voltage is present (indicating defective time delay, resistor or relay), proceed to
MALFUNCTION 12.
2.
SAFETY RELEASE INDICATOR LIGHT IS ILLUMINATED AND AUDIBLE ALARM IS SOUNDING.
Step 1.
Set OFF/VENT/HEAT switch (S1) to OFF and reset combustion control relay K8.
Step 2.
Check that fuel being used is proper for the ambient temperature per Table 1-1.
If fuel is not proper, proceed to MALFUNCTION 10.
Step 3.
Check that fuel tank contains fuel.
If fuel tank is out of fuel, fill tank with proper fuel.
If fuel tank contains fuel, proceed to step 4.
Step 4.
With switch (S 1) set to VENT purge the fuel system of air (para 1-13b).
If system does not purge, check for loose fuel connections between fuel tank and pump.
If system purges, proceed to step 5.
Step 5
With switch (S1) set to VENT, observe through sightglass for spark at burner.
If spark is not visible, proceed to MALFUNCTION 8.
If spark is visible, proceed to step 6.
Step 6.
Set OFF/VENT/HEAT switch (S1) to HEAT, reset combustion control relay K8 and observe fuel
pressure.
If audible alarm sounds immediately, proceed to step 8.
If fuel pressure fails to rise to nominal, proceed to MALFUNCTION 3.
If fuel pressure rises, proceed to step 7.
Change 4 3-7
