Bradford-White Corp U2TW50T*FRN, UTW450S60FR*N Sequence of Operation, Abnormal Operation cont’d

Sequence of Operation

Abnormal Operation (cont’d)

5.Flame Sensing Fault:

A)Flame Lost During Run: The gas control turns off the pilot and main valves and runs the blower for 15 seconds (inter-purge) The gas control increments the recycle count, if the recycle count has not reached its limit (4), another trial for ignition begins. If the recycle count has been reached, the gas control LED flashes 6 times then 3 times with a 3 sec- ond pause. The gas control waits 5 minutes before repeating the igni- tion sequence.

B)Flame Sensed Out of Sequence: The gas control only looks for pilot flame when the blower is running. If flame is present when the pilot valve is not open, the gas control proceeds to wait for flame loss and flashes 5 times with 3 second pause. This continues until flame is lost, once the flame signal is lost, the control flashes 6 times then 4 times with a 3 second pause. The control waits 5 minutes before repeating the ignition sequence.

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