34
→SOLENOIDS CHATTER WHEN ENGERIZED
In rare cases, solenoids have been known to chatter (open and close rapidly). This could be
interference from the transformer located on the control board. If this occurs, lightly pull all
wires from the control board away from control board transformer and zip tie off to one side.
→BURNER IGNITES, BUT LOCKS OUT IN 10-20 SECONDS
Look for cracked porcelain on flame-sensing rod. Moisture in cracks can ground rod to housing
and eliminate the rods ability to sense flame. If cracked, replace.
Check flame-sensing rod wire for grounding or weak connection. Follow wire from rod to
control board terminal “S”. No grounding to housing should be found.
Check grounding lug. Look for an established connection between ground lug (located on floor
of control box) and the “C” terminal on control board.
Check current on flame-sensing circuit. NOTE: The following test must be conducted while
heater has a fuel source and able to fire- even if locking out occurs after 20 seconds. Heater
must be interlocked with fan controls.
Test equipment required: Volt-Ohm meter with 50 micro-amp DC scale.
1. Set meter at 50 micro-amp, DC scale
2. Locate wire coming from flame sensor into control box, traveling to the “S” terminal
on control board. There is a factory installed break just before the board, in this wire-
make the break and add meter in series here.
3. Turn on heater unit.
4. Observe meter reading:
(1.) During lighting period, the meter may move erratically due to spark
interference.
(2.) After spark ceases, the meter reading should be constant and should read
between 10 & 25 micro-amps.
Note: A reading of a least 3 micro-amps is needed to maintain
operation. Any reading below 3 micro-amps will cause lockout.
5. If amp meter readings are above 3 micro-amps, but lock still occurs, replace board.
→
BURNER INGITES AND OPERATIES, BUT NUISANCE LOCK OUT OCCURRED
Check the following for possible solutions
(See Fig# 1, page 36):
1. Replace spark plug or gap to 1/8”.
2. Check transformer, ignition wire and spark plug. Look for cracks or grounding in wires 8#, 9#,
& 10#.
3. Check tank pressure, line and strainer for blockage. Heater unit works best with a tank at 30%
above capacity.
4. Is there possible freeze-up of regulator? If so, allow heater to warm up. Adjust vaporizer. An
improperly mounted vaporizer could allow liquid propane to freeze in upper manifold and not
allow heater to work properly. Move coils to the center of the housing, directly in front of
combustion chamber.
