OT - furnace problems

[spydrjon]

Anyone here that knows there stuff when it comes to HVAC?
Here is my dilemma:
The vent fan comes on as it should.
Then the hot surface igniter heats up, as it should.
The gas valve then opens, as it should.
FLAME ON!!!
Problem is, once the hot surface igniter is shut off, the gas shuts off.
I am thinking that one of the relays is not relaying

Any help will be met with many thanks

 

[ptschram]

Do you have a wiring diagram? Figure out how it works from the diagram and look to see what isn't happening when you need it to do it.

 

[Eric N.]

Do you have a carrier? If so then you might have the same probe on yours that I do mine.. I have had the same problem a few times and the only thing that I needed to do was clean off the black soot from a probe in the stream of flame. I use emory cloth or really fine grit sand paper... You want to clean it not ruin it.. I also make sure that the injectors are clean of buildup.. Plus, I vacum all the dust and stuff out of the area and out of the tubes that the injectors spray the gas into.. Here's a picture of the probe that I'm talking about.. Can't hurt to try that first since it's free..

 

[ptschram]

Judging from the description of operation, he does not have a thermocouple (which is what it looks like in your picture).

 

[Eric N.]

Judging from the description of operation, he does not have a thermocouple (which is what it looks like in your picture).

Could be the case but, mine does the same thing that he was describing and that's what fixes mine so I thought that I'd throw it out there..

 

[D Chapman]

Could be the flame sensor, if you're lucky.

If not, it's the circuir board.

Try the flame sensor first, as it will need to be replace at some point anyway. Plus, they're cheap. If that does not fix it, it's the circuit board. Depending on what unit you have, they could get a little pricey.