thermocouple problem?

My finished family has a seperate gas/blower unit for this space and has been working fine.

I went to turn it on (increase the heat) in the room today and no heat. the pilot is on and stays on, breaker is ok and new Round is connceted properly. System worked last fall with new round.

Could it be that the thermocouple is bad/not working? If so how difficult is it to replace?

Thanks in advance for your help.

 

Not a expert, I'm sure they will answer soon.
If I remember correctly, if the thermocouple was bad your pilot light would not stay lit, is the gas valve turned to the on position? not on the pilot position.

 

J,

comtnman is right.. If the thermocouple was bad, the pilot would not stay on..

Do you have A/C on it? If the t-stat has fan "On-AUTO" switch the fan to "ON" if that runs then your unit itself is getting power.


If nothing happens, check to make sure you are getting power to the unit itself. Even tho the breaker maybe on.. switch if off, and back on again.... Also alot of furnace has another switch/fuse right next to the unit.. Check to make sure that is on, and fuse is ok.

Also check to make sure the blower door is on, and in place..


Write back of what you got so far..

 

Is this a wall unit like and you could have a powerpile or thermopile there on the pilot that you asked about the trermocouple? You have to see if you have power at the tstat ED

 

I checked power to the tstat and it is there, turned breaker off then back on, made sure the fan door was seated properly and gas valve is turned to on position.

The pilot stays lit but when the tstat calls for heat the burners do not light. Any other suggestions?

Thanks

 

You say power at the tstat. Gas valve on. So when it calls for heat do you have 24volt power there at the gas valve?? you can check this out with a volt meter. tell me about this NEW ROUND? ED

 

Dont have a volt meter just a pencil device that detects electricity with an audible alarm ( which goes off at/near the gas valve) when it calls for heat.

The new round is you basic heat only honeywell round tstat. its a 2 wire system and took the wires from the old plate (connected to R & W posts) and reconneted them to the same connections on the new plate and worked fine in the summer.

is my diag correct does it sound like the thermocpuple? or is it time for a professional?

 

It does not sound like a thermocouple problem. Your pilot would NOT be lit if the thermocouple was bad.

You should also check to see if your system has a MANUAL RESET high limit fan control. If you can find a wiring diagram, it would be listed there. Gas valves don't fail that often so you should not suspect that until everything else has been eliminated. You would get better information if you could read ac voltage. Keep at it.