My Blower won't stop

[oriondad]

Here's the problem. My blower runs constantly with no heat. Just recirculating cold air.

specs are: a Ruud gas forced furnace, approx. 8 years old. We have lived here 3 years and have not cleaned it.

Seems like it could be a limit switch of some sort. After reviewing several other threads, seems like it might be due to the furnace NOT being cleaned....

A man with little to no handyman skills!!!!!

[imeduc]

Ckeck the filter is it clean .the AC coil clean. Hit on the side of the furnace with your hand hard and seen if that stops it.Look at the wire schematic there and see where the blower relay is check it out.

ED

My mistakes dont define me they inform me.

[LazyPup]

check the little switches to make sure the T/stat is actually set on heat,,,not on manual fan.

[Hube]

I would suspect a faulty fan relay (contacts burnt. If relay is ok, then check out contact terminals on T stat Fan on/manual switch.

[oriondad]

Problem solved.

The upper limit switch overheated. The techy checked it with what I would guess was a voltage meter (something I didn't have), and found no current. He tapped it a few times and then it was ok.

Could have been caused by a dirty filter. We clean our filters pretty regularly, but possibly this time the dust was much heavier. My wife commented that the basement gets more dirt than anywhere else.

So, if you happen to have this same problem, find your high limit switch, at least tap it a few times and try your furnace again.

Cost was 145, and 10 hours of 50 degrees.

thanks for your help, you folks were right on. The limit switch.

A man with little to no handyman skills!!!!!