Honeywell CT3300 Heat switch

[JDCam]

T-stat: Honeywell CT3300 programmable
Furnace: York Diamond 80 - Natural Gas

Furnace is about 10 years old, T-Stat maybe 6.

Heres the problem:
Every 3 or 4 days the Furnace stops coming on. When I look a the t-stat, the current temperature is too low, but the heat indicator is on. Turning up the heat does nothing, but simply switch to off then back to heat and it starts up no problem. will run fine for a few more days.

The Heat indicator is telling me that it knows the furnace needs to come on, but it is not responding. Is the t-stat not getting the signal out, or has the furnace stopped responding.

Not sure If i should swap out the t-stat or call for service on the furnace. any way to test this? it is very intermittent and I cant make it happen on demand.


Cam

[paul52446m]

T-stat: Honeywell CT3300 programmable
Furnace: York Diamond 80 - Natural Gas

Furnace is about 10 years old, T-Stat maybe 6.

Heres the problem:
Every 3 or 4 days the Furnace stops coming on. When I look a the t-stat, the current temperature is too low, but the heat indicator is on. Turning up the heat does nothing, but simply switch to off then back to heat and it starts up no problem. will run fine for a few more days.

The Heat indicator is telling me that it knows the furnace needs to come on, but it is not responding. Is the t-stat not getting the signal out, or has the furnace stopped responding.

Not sure If i should swap out the t-stat or call for service on the furnace. any way to test this? it is very intermittent and I cant make it happen on demand.


Cam

One way to check is to go to your furnace find the low volt thermostat wire post marked r and w. Put a wire on both of them and bring your wires out side of the furnace so you can get to them. Cap them off. Make sure you leave the wires on those post that were there. Now when your furnace doesn't come on just go to the furnace and put those two wires together , if the furnace fires than the problem is in the stat or wiring going to the stat.
if it doesn't fire than you have a problem in the furnace. Later Paul