10-27-2007, 11:24 AM
At the end of this summer season, I replaced the control board on one of my American Standard furnaces. The fan relay was bad. It's just now that I am using it in the heating mode. When it comes on(cold start) the draft inducer motor comes on and a few seconds later it shuts off for about 1 to 2 seconds. Then, it comes back on and I have regular ignition and heating cycle? So far, I've noticed that it does not happen when I shut the unit down(via thermostat) and restart a few minutes later while the exhaust vent pipe is still warm??? Could it be a draft sensor problem?