Furnace overheating

Old 03-10-12, 05:13 PM
Thread Starter
Join Date: Mar 2012
Location: Canada
Posts: 2
Upvotes: 0
Received 0 Upvotes on 0 Posts
Furnace overheating

Hi, I have a Keeprite NTGM100EHA2 (DC 90) furnace that overheats at the limit switch (or flame rollout switch) and trips. I have to push the little reset button on the limit to get the furnace burners on again. I changed the limit switch in case it was defective (only $10), still the same problem. I changed the furnace filter, opened all registers, made sure all return air vents clear, checked exhaust pipes for blockage, opened window to make sure furnace intake is getting proper air but still same problem. I noticed the limit switch is tripping not because of flame rollout, but when the furnace reaches its set temp. and the burners shut off and then the ventor motor shuts off, thats when the limit switch trips, and the combustion chamber box feels very hot by touch, hotter than normal . Anyone out there have this same problem ? Any suggestions would be greatly appreciated. Thanks Tom
Old 03-10-12, 06:35 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 6,530
Received 95 Upvotes on 88 Posts
Is your evaporator (cooling) coil clean?

Old 03-11-12, 07:56 AM
hvactechfw's Avatar
Join Date: Jan 2011
Posts: 5,491
Upvotes: 0
Received 4 Upvotes on 4 Posts
IF your flame rollout is tripping you need to call a PRO! That is usually a sign of bad things happening in the heat exchanger. Call a PRO! Could be very dangerous to continue to try to run the furnace!

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