After numerous tests, it would appear that my Fan Timer module (Honeywell st9120c 2010) is bad. In particular, I can see the lead to relay K1 is burned and I get no power on either output side of it (one is supposed to be for constant fan and the other for auto - so they should be energized alternately).

So, I have a new timer module ordered, but it is cold in these climes, so...

I have alternately hooked the main blower through the Humidifier jack which is is energized as soon as the inducer motor fired up. As far as I can tell from both the wiring schematic (Product (http://customer.honeywell.com/Honeywell/ProductInfo.aspx/ST9120C2010)) and actual tests, this seems identical to having it wired for Constant Fan.

While not planned to for longer than a couple of days, is this stupid for an reason?

I was worried that having the circulation fan blowing would prevent ignition, but this does not seem to be a problem.

Thanks for any insights.

You can put your motor lead on the constant on pin and it will not bother the ignition sequence of the furnace, as you stated, the fan will just run all the time...

Thanks. The constant pin is the "open" side of the burned relay and doesn't get power either. As far as I can tell the Himidifier pin is also always onas well.