I activated the thermostat, draft fan came on briefly, ran for maybe two full seconds and stopped. I re-set thermostat and again draft fan came on but this time even shorter than the first. Third attempt did nothing, no draft fan. Control board is hot, LED not blinking but steady. I metered draft fan 110vac contacts, no voltage. I disconnected draft fan 110vac to board and ran the fan with a jumper so its not the fan. My guess is the board mounted power relay but there are two, I don't know which to replace. I have a junk board to get a relay but I don't want to waste my time. Any one know which is which ? Any suggestions ? Thanks