Bradford White RG2F40S*(N,X) Service Manual page 11

Abnormal Operation (cont'd)
2. Temperature Sensor Fault:
A) Temperature Sensor Open Circuit: The gas control immediately turns off all
outputs and proceeds to flash 8 times then 2 times with a 3 second pause. The
status self clears if the fault clears for at least 15 seconds.
B) Temperature Sensors Not Reading the Same Temperature within ±5°F: The gas
control immediately turns off all outputs and proceeds to flash 8 times then 2 times
with 3 second pause. The status self clears if the fault clears for at least 15
seconds.
C) Water Temperature in excess of ECO (Energy Cut Out) Limit: The gas control
immediately turns off the pilot and main valves. The gas control LED proceeds to
flash 4 times with a 3 second pause.
To reset the gas control, rotate the setpoint knob to the minimum setting for at least
6 seconds before returning to desired temperature setting.
3. Pressure Switch / Blower Temperature Switch (Safety Circuit) Fault:
A) Pressure Switch Closed at Start of Call for Heat: The gas control proceeds to
flash 2 times with a 3 second pause. The gas control waits 2 minutes, and then
turns the blower on for 60 seconds. The blower turns off after 60 seconds, and
the control waits for the pressure switch to open.
B) Pressure Switch Failed to Close: The gas control runs the blower for 60
seconds waiting for the pressure switch to close. If the switch does not close in
60 seconds, the blower turns off, and the control flashes 3 times with a 3 second
pause. The gas control waits two minutes before turning on the blower for
another 60 seconds to see the circuit close. This cycle repeats as long as there
is a call for heat or until the circuit closes.
C) Pressure Switch / Blower Temperature Switch Opens During Burner Operation:
The gas control turns off the pilot and main valve and runs the blower for 15
seconds (inter-purge) waiting for the pressure switch and/or blower temperature
switch to close. If either switch fails to close, the control proceeds as described
in 3B above. If the circuit closes again by the end of the inter-purge, the recycle
counter is incremented.
another trial for ignition begins. If the recycle count has been reached, the gas
control turns off the blower and flashes 6 times then 2 times with a 3 second
pause. The gas control waits 5 minutes before repeating the ignition sequence.
If the recycle count has not reached its limit (4),
Sequence of Operation
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