My 10 year old Raypak RP2100 service light went on and will not heat up. I opened up the panel to view the circuilt board and see a red led lit.

The board shows:

OVERTEMP {LED} SENSOR {LED} FAIL

The led between SENSOR and FAIL is lit. I'll take this at face value and consider some kind of sensor has failed but which one and how to confirm which one. Is there a way to short the sensor leads or do some 'trick' to let the circuit board know all is ok to lit?

This happens as soon as the unit is turned on so it is not possible for an over temp situation. This happened last week and I could swear that both LED's were lit but today only the 1 LED is lit.

I did several Google searchs and did not find anything. We must have an 'old' version since most postings had to deal with a display panel that will show error codes but my panel has no such display, only the rocker switch and lights.