Carrier furnace blowing cold air.

Reply

  #1  
Old 12-21-08, 10:20 PM
Member
Thread Starter
Join Date: Dec 2008
Posts: 2
Received 0 Votes on 0 Posts
Carrier furnace blowing cold air.

Hey all, I'm new to these forums and hoping someone can help me here.

I have a Carrier natural gas furnace in my attic. Last winter was my first winter in this house and although I didn't want to use the gas furnace for cost reasons, I did want to get it set up as a backup heat source for the really cold nights if my electric space heaters couldn't cut it.

At first, the furnace didn't work, it turned out to be the thermo-coupler which is pretty standard stuff. I had a friend come over to change that out with a new one and get the pilot light lit. He told me before he left that I should mess with the thermostat to make sure it would kick on and off properly so I did. All was fine for about 15-20 minutes, after which the furnace began blowing out cold air.

I had my boyfriend go up in the attic to make sure the pilot light hadn't gone out and he verified that it was still lit. We shut off the gas at the main valve to the furnace and just left it.

This year I was hoping to get the furnace going again so I had someone come out to look at the furnace. (Not a professional service tech) He said everything looked okay with the furnace and said it was probably my thermostat. I bought a new thermostat and installed it. The furnace worked like a charm, kicking on and off fine and blowing warm air. It worked great for about 6 hours, but then began blowing cold air again.

The guy who suggested the thermostat said to turn the thermostat all the way up and kick the furnace on...if it blew out warm air then the problem was most likely the fan and limit switch. I tried this....but it still blew out cold air, even with the thermostat set to 95 (the max temp setting).

Another friend suggested it might be the regulator which would run me about $300...way more than I want to spend on this furnace which is not ancient but still several years old. Not to mention, it'll cost me $76/hour for a professional Carrier service tech to come out.

Any ideas what the problem might be? Is this something I can fix myself or will it require a service professional? If it will....I'll just have to shut off the gas to it and forget it.:helpme 2:
 
Sponsored Links
  #2  
Old 12-22-08, 05:38 PM
Temporarily Suspended
Join Date: Jul 2008
Location: NY
Posts: 10,986
Received 0 Votes on 0 Posts
Troubleshooting Guide - Carrier

That's the troubleshooting guide from Carrier. In your case the thermostat is good, the gas is igniting, the breakers are on, since the motor is running. Let's check the filter. What year was it last replaced?
 
  #3  
Old 12-22-08, 07:24 PM
Member
Thread Starter
Join Date: Dec 2008
Posts: 2
Received 0 Votes on 0 Posts
Thanks for the reply Pulpo. I pulled the grate down off the intake and what do I find?? No filter at all. Makes me wonder if the previous owners ever bothered with them? Because if they had, surely there would have been an old one still in there.

So to answer your question, I have no idea how long it's been since the filter was changed since there wasn't one in there.

If something is clogged or dirty and is the reason for the furnace to work fine then suddenly blow cold air, what would it be and is it something I can clean myself?
 
  #4  
Old 12-22-08, 08:08 PM
Temporarily Suspended
Join Date: Jul 2008
Location: NY
Posts: 10,986
Received 0 Votes on 0 Posts
The first thing I would do is install a filter and run the unit again. Besides keeping the air clean, it may be needed to regulate the air flow. If you're still getting cold air, remove the inspection cover, hold the safety button in by hand, the fan motor should start and the burner should light a few seconds after. If that isn't happening, the circuit board could be bad.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
 
Ask a Question
Question Title:
Description:
Your question will be posted in: