Furnace exhaust fan question

[manleygt]

I have a 1995 Intertherm furnace in my home. I noticed this morning that the ventilation fan keeps kicking off and on. At times it does this every 5 seconds and then others it cycles like "normal". I switched thermostats to see if it was that since we recently switched to a digital model. It made no difference. In addition, it will do this when the thermostat is set to a cooler temperture than what it really is and the furnace is not even producing heat. It does it when it is at a cooler temp too. Any ideas?

[rmurray]

There are others here with more repair experience than I have, but it sounds like a common problem that Intertherm has had in the past. The cycling of the blower fan is controlled by a temperature limit switch inside the heating box of the furnace. It is not uncommon for limit switches to malfunction. A quality furnace repair person should be able to test and diagnose this problem and repair at a reasonable price. This part is probably available at the parts store listed on this web site just below this post. If I sound way wrong, I trust others will help correct me.