Furnace Or T'stat Problem? - HVAC - DIY Chatroom Home Improvement Forum

Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC


Thread Tools Display Modes
Old 10-14-2010, 01:42 PM   #1
Join Date: Oct 2010
Posts: 1
Rewards Points: 10

Furnace or T'stat problem?

I have a 25 year old Trane Forced Air furnace, central air and a honeywell cronotherm 3 t'stat. Last Saturday morning, I lit the pilot light for the furnace and set the switch on the t'stat from OFF to HEAT. The fan switch on the t'stat is set to AUTO. As soon as the t'stat calls for heat, the burner and fan start at the same time. It has NEVER done that before. The unit continues to run for a few minutes, burner shuts off, fan runs for another couple minutes and shuts off - for about 5-10 seconds. Fan comes back on for 1-2 minutes and shuts off again. The fan limit switch appears to be set at 90 degrees off and 130 degrees on. I didn't have any trouble with the t'stat during the summer months with the AC. Could the fan limit switch or t'stat be bad?


kwf739 is offline   Reply With Quote
Old 10-14-2010, 03:22 PM   #2
HVAC / Plumbing
Join Date: Feb 2009
Posts: 1,801
Rewards Points: 1,000

If it's the old type fan/linit switch ( the type that rotates around) These have a spring & it rotates around by heat. Since it's had heat on it for 25 yrs it could have gone bad. If you jump it out at the t.stat r&w & it still does the same thing . It's probably that fan/limit switch


kenmac is offline   Reply With Quote

Thread Tools
Display Modes

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

Similar Threads
Thread Thread Starter Forum Replies Last Post
Heil Furnace Burner Problem timothyr HVAC 79 02-12-2014 07:01 PM
Help troubleshooting furnace problem robert_ HVAC 21 02-15-2012 08:04 AM
Old Silver-Line furnace problem avro1 HVAC 9 03-18-2010 12:01 AM
problem with Furnace staying on. rdavis HVAC 4 12-01-2009 09:19 PM
Help - Problem with Oil Fired Forced Air Furnace JohnF HVAC 13 01-31-2009 09:04 PM

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1