Coleman furnace maintains temp but has problems heating


Old 12-17-08, 11:12 PM
Thread Starter
Join Date: Dec 2008
Location: Portland, OR
Posts: 1
Received 0 Votes on 0 Posts
Question Coleman furnace maintains temp but has problems heating

I have been having intermittent problems with our furnace, a gas Coleman/Evcon model BGU05012A with a Honeywell RTH230B programmable thermostat. The house is 90 years old and small, there are 4 vents upstairs and 1 in the finished half of the basement (the basement vent is only off the plenum by about 1 foot of duct). I'm not sure of the age of the furnace, hopefully the model # will give that info.

The problem shows itself when the furnace is trying to heat the house. The thermostat is set to keep the house at 60 during the night and then heat to 66 in the morning when we get up (cold by most people's standards I know, but it works for us). It usually gets to about 63-64 then the furnace will shut off and not do anything until we turn it off and on at either the breaker or thermostat, however, the thermostat still has the flame icon in the corner which shows that it wants to be heating. The colder it is outside, the more pronounced the problem is.

Once I get the house to 66 (or any temperature we set it to as we sometimes override the program in cold evenings) by cycling the power switch 2-3 times, it will begin to cycle on and off normally and have no problems maintaining the proper temperature as long as the basement vent is closed. When we had the basement vent open it would still randomly stop working about 1/3 of the time (a little more the colder it gets outside).

The significant effect of the basement vent and noticeable effect of the colder weather, leads me to think that its some sort of heating capacity issue, but really I'm not sure. We live in Oregon and as nighttime temperatures dropped into the 30s it has gotten a lot more noticeable.

So my question really is if there is some sort of part or adjustment that may be bad or out of whack or is the furnace truly just too small to heat the house? Any help would be greatly appreciated!
Sponsored Links
Old 12-18-08, 07:24 PM
Join Date: Dec 2005
Posts: 458
Received 0 Votes on 0 Posts
It sounds like your furnace is plenty big to heat your house. What you are experiencing is a lockout condition. From what you explained, it seems to run only a certain length of time before lockout. Colemans sometimes used the hot surface ignitor also as a flame sensor. It may need to be replaced. Also, check the condensate drains. Take the drain system apart as far as you can and blow/rinse out the hoses and pipes.
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
Ask a Question
Question Title:
Your question will be posted in: