SERVICE PROCEDURES AND ADJUSTMENTS
THERMOCOUPLE TEST
1.
Unscrew thermocouple fitting from safety valve.
2.
Install thermocouple test adapter finger tight
plus a quarter turn.
3.
Install thermocouple into test adapter finger tight
plus a quarter turn.
NOTE:
Over tightening can cause thermocouple tip
to short out.
4.
Set VOM to DC millivolt scale and connect (+)
meter lead to pin on thermocouple adapter and
(-) meter lead to thermocouple.
5.
Light pilot flame.
6.
Verify that
thermocouple is sufficiently immersed in
flame. Adjust pilot valve to allow more gas flow if
necessary.
7.
With thermostat off, allow pilot to burn for 3-4
minutes to stabilize voltage output from
thermocouple.
8.
Verify thermocouple output voltage.
A.
If 25 - 35 millivolts is measured, the
thermocouple is functioning properly.
B.
If less than 17 millivolts is measured,
install a replacement thermocouple.
9.
Remove test adapter.
F25383 (510)
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