Chapter 4
Troubleshooting
Yes
The safety system for the heater does not have the correct initial setup.
Check that the flap for the sail switch is not stuck in the open position. If the sail
switch is not physically stuck open, check that the resistance across the sail
switch is above 1 MΩ when the heater is off. If the resistance is below this valve,
the sail switch needs replacement.
Problem: Fan Runs But Heater Fails to Ignite
With the gas off, start the heater by turning up the thermostat to the maximum temperature. The
red light should turn on a couple seconds after the fan starts and you should hear a faint clicking
noise fifteen to thirty seconds after the blower starts. If you do, then:
Rule out general problems.
Carefully check the fuel system. Check that the propane
tanks contain fuel, all gas lines are undamaged, and all fittings are tight. Check the
connections at the thermostat for problems. Remove the cover of the heater and check the
wiring for damage or loose connections and the components in the heater for obvious
damage. Check that the heater is getting at least 12 VDC.
Inspect the spark ignition system
. The spark ignition system should create one spark
across the tip of the spark probe in the combustion chamber on each faint click. The spark
can be in an incorrect location for any of the following reasons: damage to the spark
probe wire, loose connections, and deposits on the spark probe. To access the spark probe
to check it for deposits, removing the access panel on the side of the heater by the
combustion chamber. The metal tips of the spark probe should only be slightly rounded
with an 1/8” gap at the tip. In addition, the insulator on the probe should have no cracks
or chips missing and only have light deposits on the insulator. If the spark probe is
damaged or excessively round, it should be replaced. If the spark probes only has
deposits, carefully remove them with a damp rag or abrasive plastic pad.
The small blower may not be working.
With the gas off, check that air is flowing
though the combustion chamber and that the small blower is turning. If it is not working,
check for loose connections or obstructions or damage to the blower. If you find nothing
obvious, remove the blower and test it at 12 VDC to see if it is functioning correctly.
If the red light does not come one and you don't hear the faint clicking noise then
The sail switch or high temperature switch may be malfunctioning
. If the sail switch
fails to close or the high temperature switch is stuck open the heater will not attempt to
ignite. Also loose or damaged wire to either of these items will cause the same problems.
Check the wiring to these two items. With the power off to the heater, use a multimeter to
check that the resistance of the the high temperature switch is less than 1 ohm. If it is
higher, it should be replaced. Also, check if the sail switch closes when the heater runs by
disconnecting the wiring to the sail switch and checking if the resistance drops to zero
when the fan is running. If the wiring and two switches check out ok, refer to the
troubleshooting tips above for this problem.
If the red light comes on but you don't hear the faint clicking noise then
This indicates either a short in high voltage line or a malfunctioning ignition
module
. Check the high voltage line for damage. If no problems are found, remove the
high voltage wire from the spark probe on the combustion chamber (it can be accessed by
removing the access panel on the side of the heater by the combustion chamber). With the
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