Furnace repair? Help.........

[saltymac]

Hello all, Merry Christmas and a Happy New year to all!!
If there are any furnace guys/gals out there that can give me a hand on fixing my furnace, it would be greatly appreciated.
First off it works sort of, my house isnt freezing, but could be warmer.
Im not sure if Im right but the steps a furnace take to complete a cycle are:
1. exhaust blower starts
2. glow plug fires
3. gas release/ignites
4. glow plug off
5. chamber/temp limit reached/ circulation blower starts
6. temp from theromostat reached/ gas off
7. cool down/blower off
8. exhaust blower off
like I said, Im no expert, but sometimes it completes the cycle, but 9/10 it shuts off shortly after the gas is released and glow plug goes out. The circulation blower doesnt even kick on before the whole thing shuts off. I have a comfortmaker II which has an
LED display for troubleshooting....... it flashes 6 times, but the manual only goes up to 5.............so if anyone knows how to fix this and is in the holiday mood of giving, I couldnt thank you enough.
Merry Christmas and God bless all!!

 

[renogaw]

you have a flame sensor somewhere in there that you don't know about. if it doesn't sense a flame, it assumes the gas is just pouring into the house. if you see a flame firing, then the sensor is either bad, or the control module isn't getting the signal from the sensor and may be bad. I'd give the manufacturer a call and see if they have any technicians that can come out and check it out, or even find out why you have more blinkies than listed.

 

[jennythebugg]

this is a great forum i have fixed dryers, fridges, stoves and an a/c just by reading through the questions and answers on there or you can sign up and post your own question for the samurai appliance gurus
http://fixitnow.com/

 

[bessycerka]

or, the sensor/relay that senses that the heat from the unit has reached the point that the fan should come on has gone kaput. This causes the fan not to start, and the heat to build up, causing the thermal sensor to shut down before the furnace melts with out the fan blowing the hot air out of the plenum.

 

[scsinet]

Originally Posted by renogaw
you have a flame sensor somewhere in there that you don't know about. if it doesn't sense a flame, it assumes the gas is just pouring into the house. if you see a flame firing, then the sensor is either bad, or the control module isn't getting the signal from the sensor and may be bad. I'd give the manufacturer a call and see if they have any technicians that can come out and check it out, or even find out why you have more blinkies than listed.
+1.
Oftentimes the flame sensor gets gunked up with carbon deposits and starts working unreliably. What you describe... the flame going out after a few seconds is almost definitely flame sensor related.
It should be easy to find... just a little stiff wire that sticks into the flame, secured with a sc-rew.
Just remove it, clean it up with some steel wool, and reinstall and you may find that things work much better.

 

[saltymac]

Thank you all for the replies...........I was trying to avoid a service call and all the fees that come with it. Im gonna try the flame sensor, that makes sense, plus its only $15 bucks, well worth it if it works. Thanks again and Happy Holidays