Gas Furnace Symptom of Flame Sensor Failure

1986 Furnace. I kept hearing a sound like a candle being blown out. Went under the house with the tech. 1st thought it was the Gas Valve, but voltage drop upon flame out indicated a bad flame sensor assembly. $200 repair

Category:

Science & Technology

Tags:

• Gas
• Furnace
• diagnosis

[jimthepianoman]

This is my 1986 furnace. I think it's a trane brand???

the Tech didn't check the connex as I recall. He may have tried polishing w/ steel wool... any how it's showing it's age now. We replaced the motor last summer of 08.

Cheers, Jim

[poopsmashed]

Rarely is a flame sensor bad, maybe dirty, but thats a pressure switch most commonly.

or the hose and or orifices that the hose connects to on the induced draft housing and or the pressure switch, moisture and carbon will make it impossible to sense the induced draft running or it woill waver open /closed as this is. limit may be cycling too need to use a meter.

[tribe1]

Did u find a resolution to your problem?

[bblazeff1]

If you decide to disconnect your ground wire and clean it, which is normally unnecessary because dust don't get in between the connection, if it does you would have a very loose connection, be sure to disconnect power to your unit as the electricity can and will kill you or cause serious harm to you ..

[Scoobie382]

Try everything you can do yourself with out dangering yourself first before calling a professional. I find that when I deal with some of these HVAC guys they often lie, not all of them but some. Best bet is to call at least two and get two seperate opinions, and watch them, afterall its your furnace and more importantly YOUR MONEY!! Im not trying to be an HVAC hater but ive had a couple of problems with them myself. Get the estimate in writing. Good luck!

[Scoobie382]

Also take and disconnect your ground wire and clean it. When the furnace gets dusty inside, sometimes it gets inbetween the ground wire and wont allow it to get a good ground connection and it wont allow the furnace to stay lit

[tpdeehan]

It's a Carrier and your 3 wire warp (green/yellow and white... bottom of video) switch is short cycling the main burner. There is no flame senser on this furnace.

[primalscreamz]

the 3 wire pilot assembly needs changed

[pclle]

I've never seen the pilot at the primary air entrance so close to the orifices before