[masraum]

I have a gas furnace. I think my fan is failing to come on every time when the heat comes on. The fan will come on if I turn the fan to "on" at the thermostat.

To me, that says that there's a relay going out (intermittent fan).

I'd think that replacing the relay should be relatively cheap and easy if there was somewhere that I could get the relay.

There is a fan that blows hot air out of the vent (out through the roof). I've gone up when the thermostat said that the heat was "on" but the fan was not on and found that the vent and a couple of spots on the furnace were very hot. I think that's a bad thing.

UNtil I get this fixed, I'm just going to run the fan 100% of the time. Any ideas, should I try to find the relay and replace it myself or should I just call someone?

I think the furnace is about 10 years old give or take a year.