We use a round Honeywell thermostat that worked just fine last winter. It was working just fine yesterday and today for our air conditioner. When we switch it to heat it goes black like we turn it off.Our furnace uses an electronic pilot which was working correctly last winter when we discontinued our heating cycle.Please offer any suggestions that might help.Thank you.George Mann
Make : Carrier Furnace and Air, Honeywell Thermostat
Checked furnace wiring.
Checked furnace fan.
Checked furnace pilot.
Everything appears to be working correctly.
This can be decide but it requires removing the top section of the thermostat and crossing the red and white wires. If the Furnace starts and runs appropriately then it is a defective thermostat. If the furnace does not run accordingly the issue is with the furnace. I am available for follow up.
I have changed the wires three times but am not sure it was a good test.
I need to stop for some air to breath.
Will try again after lunch and advise you of the results.
Keep me posted
I haven't done my retest yet.
On my origional test that you suggested I wasn't sure of the results because the door was off the bottom of the furnace and the safety lever was not depressed.
On the test that I tried, reversing the red and white wires, The fan would not even operate. After replaceing them to the origional possition the fan still would not work which it had been before the trade. Hope I didn't damage anything..
I must have used nonsuccint terminology for you, I apologize. What I meant by crossing them was to twist together or touch together thus bypassing the thermostat. Try that and let me know if that works. If not the worst case will be a small 3amp fuse on the furnace circuit board. Try , with the door on and power on touching the r terminal wire and the w terminal wire together so they make contact.
Tried the wires connected both ways.
Tried the 80 degree setting with and without the fan.
The fan is working and the light on the thermostat is working.
We waited several minutes in each condition hoping that more time might cause some change.
Using natural gas which we also use for our dryer and range.
I just found more information from you.
I will try the twisting for direct contact.
I don't know where the fuse is located from your description.
I don't see any circit board. Is it on the furnace or the outside unit?
The pilot is electronic. The furnace is gas.
Information on my Honeywell Thermostat:
Left yellow and green box--3679745 Assembled
(NNN) NNN-NNNN in Hungary
Red block at bottom---tabs 1 2 & 3 all set to the right.
Information in the middle---
item 3--F Off 32007714-001 Rev. A
White tab in the green rectangle on the right is in the center.
Numbers in the black box next to the red block at the bottom:
These are all the identifying marks that I have found.
please check the circuit board for a red flashing light in the blower compartment
I don't know where there is a circuit board.
If less than 10 years old there is a circuit board in the blower compartment
It is more than 10 years old but has been working great until this restart.
Well, it had a good run. Better than some of the vehicles Ive had....
Carrier Air Conditioner
59---Made in U.S.A.---99NA506153A
Have you located the circuit board?
Did you receive the information I sent about the Thermostat and the Model, Serial No., etc. for our Carrier Furnace? Two seperate replies.
It is everything I can locate at this time.
Remember that it is a gas furnace.
Have you located the circuit board inside the blower section yet? And located the blade fuse?
I have not located either of these.
Are these on a gas furnace?
I don't recognize a door.
I just work with upper and lower panels on the side with the vent.
Can you direct me to the area with a door?
Did you receive the Model information that I sent?
facing the front of the furnace the top door will lift up and off. Then the bottom door will remove the same way.
That is the same place that I have been working.
We replaced the run capacitor in this area last year.
There are gas valves in the top portion and several burners.
The bottom has a lot of wiring but no fuses that I can spot.
Do you see a control board that the thermostat wires attach to?
The thermostat wires just attach to other wires from the furnace?
I'm an old man that has trouble seeing and doing things.
There is a cluster of wires coming from from the pilot and disappearing into the bowels of the furnace. At one point there are two wires that go to the only thing that looks like a circuit board. there are only two terminals and no fuses on this board or anywhere in the lines that I can detect.
I always like to be able to assist a nd help fix things, but here I think it would be best to call for service. It sounds as though you have an internal issue with the furnace. Sorry I could not help more but safety is the number 1 priority.
Thank you for you efforts.
I was hoping that the Model, Serial Number, etc. might be the difference.
I don't think the problem is dangerous. It is a repetitive condition that occurs on the first restart every year.
Does anyone else want to offer a suggestion?
I will open this up and let the others have a look for you.