TM 9-4520-272-14&P
0016 00
Table 1. Troubleshooting Procedure for Large Capacity Field Heater (LCFH).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
13. Heater starts, displays error
Step 1. This error code indicates that
Step 1. If pressure at burner startup
code: S412 but continues to
the heat exchanger over-temperature
is at high fire pressure of 80-90 psi,
run
switch SW4 has been activated. Turn
this would be cause of S412 soft
power switch to OFF. Check Fuel
fault. All troubleshooting must be
Solenoid Valve FS2 IAW WP 0032 00
done within 15 seconds of startup as
to determine if it is stuck in a Closed/Hi
this ensures a Lo-Fire condition in
Fire Position. Check pressure on nozzle
the burner.
pressure gauge near burner and verify
that pressure is approximately 50 psi
Step 2. Shut down heater and
when burner is first started.
disconnect fuel line from fuel valve
solenoid FS2 (WP 0032 00) and
place end of hose into approved
container. Start heater. If, after
disconnection, gauge still reads 80-
90 psi then there may be a blockage
somewhere between fitting and
check valve or inside brass nozzle
adapter. Check for contamination of
check valve or nozzle adapter.
Step 3. If after disconnection of fuel
line in Step 2, pressure on gauge
falls to approximately 50 psi, then
fuel solenoid valve FS2 requires
replacement IAW WP 0032.
14. Heater starts, displays error
Step 1. This error code indicates that
Step 1. Verify that there are no
code: S411 but continues to
the heat exchanger airflow has been
obstructions to the air inlet duct. Flip
run
blocked or restricted. Turn power switch
RESET switch and attempt restart.
to OFF and inspect air inlet duct.
Step 2. Check for loose inlet fan. A
visible wobble or rubbing on the fan
housing would be evidence that inlet
fan is loose. If this is suspected,
retighten inlet fan assembly IAW WP
functioning, replace IAW WP 0038
Step 3. Check air sensor hose from
bulkhead to main control box and
ensure that it is connected and not
kinked, cut, or damaged in any way.
If missing or damaged, replace by
cutting a length of hose from bulk
supply.
0016 00-4
