Page 1 of 1

furnace not staying lit

Posted: Thu Feb 21, 2008 6:52 pm
by JHartsock
I have a coleman 7995C856 that I have been having problems keeping lit. The booster motor runs without the furnace running. This furnace will go out when there is no wind so I know it's not a draft problem. The thermalcouple has been replaced twice and the pilot is non adjustable.
From reading the posts here and the troubleshooting page it sounds like the blowermotor with the centrifugul switch.
I have had 2 difrent people look at this at $70.00 a visit and it's still going out. What does it sound like to you?

RE: furnace not staying lit

Posted: Fri Feb 22, 2008 1:16 am
by Robert
Hi,

Does everything, including the booster motor w/centrifugal switch stop or is it just the burner and/or pilot light going out ?



Thanks,
Robert

RE: furnace not staying lit

Posted: Fri Feb 22, 2008 4:23 pm
by JHartsock
Just the burner and pilot go out. The booster motor is still running with the furnace(and house) stone cold. Sometimes we can here a strange click when the furnace tries to light. When I check it it's out. Also sometimes when the booster motor is still running I can flic the silverdollar size unit next to the blower motor and it will quit running, then I relight the pilot.
Is that the centrifugal switch or is it internal with the motor?
This furnace might run for a week without going out then it might go out 2 or 3 times in a day. Strange

RE: furnace not staying lit

Posted: Sat Feb 23, 2008 9:26 am
by JHartsock
Furnace was out again this morning. Everything out this time,booster motor and pilot.

RE: furnace not staying lit

Posted: Sun Feb 24, 2008 2:09 am
by Robert
Hi,

Without testing the circuitry, it is hard to say what exactly is causing it.


The booster motor must be running and at designed speed or nothing will work.


There is a booster relay inside control box that signals booster to start.


Centrifugal switch is inside the motor.


Could be booster motor, booster motor relay, gas valve or a combo of those.


Thanks,
Robert

RE: furnace not staying lit

Posted: Sat Mar 01, 2008 9:22 am
by JHartsock
Robert,Can I test any of these componants without calling someone in? Can the gas valve be taken apart and cleaned? I've heard they might get gummed up. Thanks Jeff

RE: furnace not staying lit

Posted: Sat Mar 01, 2008 4:44 pm
by Robert
Hi Jeff,


You can test most of it to narrow down problem. Gas Valve is not recommended as a repair part and should not be taken apart.


The can/do get gummed up sometimes, but it is advised to replace when this happens.


Go here to pay fee for testing steps on items that you can check:

http://www.mobilehomerepair.com/Order4b.html


This will cover 1.5 actual hours of email correspondance.


Thanks,
Robert