Furnace not coming on with programmable thermostat

[home owner]

I may not have accurately described the problem with my Totaline P474-1035 programmable thermostat.

The furnace does turn "On" and "Off" (so the thermostat wiring is OK) but the furnace doesn't respond to the "Heat" setpoint on the thermostat.

For example, if the setpoint is 82 degrees, the furnace doesn't come on when the house temperature drops below 82 degrees (sometimes, the furnace doesn't come on when the house temperature falls to 73 degrees).

When I push the "UP" button so the display shows 90 degrees, the furnace won't come in for a looong time (even hours!)

[Ed Pawlowski]

Furnace is not getting the signal. Battery fresh? Try a Honeywell T-stat. Very accurate.

[home owner]

The thermostat has 2 AA batteries. I replaced both batteries about 10 days ago (and "Yes", they're installed correctly)

[home owner]

Should I just replace the Totaline programmable thermostat with a manual (non-programmable) thermostat?

[home owner]

Should I just replace the Totaline programmable thermostat with a manual (non-programmable) thermostat?

[Ed Pawlowski]

Programmable is fine, just get a reliable brand like Honeywell, Robertshaw.

As long as the heat is coming on if you bypass the T-stat you can be sure that is not the problem. The thermostat is just a switch that signals the heater to go off or on.

[Bud]

Sounds like some component failed in the electronics. You need a new thermostat.

[Bill]

Have you tried jumping the thermostat yet?

[home owner]

The furnace does turn "On" and "Off" (so the thermostat wiring is OK)

[makolber]

so you say it will come on,,,

what do you have to do to make the furnace come on?

maybe the thermostat is set for some weird mode like keep off or something.

can you clear it of all programming and start from scratch?

m

[home owner]

I have cleared all programming and started from scratch.

The clock is set to the correct date and time The Heat setpoint is 82 degrees for every day (SaSuMTuWThF) and for all time periods. The Program Switch is at the RUN position The Mode switch is at the HEAT position The Fan switch is at the AUTO position

[Bud]

Thats entirely up to you.... Both will work.

Personally, I found my programmable t-stat was more trouble than it was worth. But I am not on a routine, so I was constantly having to change and bypass the settings, not to mention changing batteries.

Then I replaced the furnace, and had a professional furnace guy come to modify the duct work. He told me to use the non-programmable t-stat that came with the furnace, saying it was calibrated for that furnace. (I'm not sure if I believe that), but I put that one on the wall, and have not gone back to the programmable. I have a constant temperature, No more fussing with it or batteries to change. If I go away for a whole day, I may lower the temp about 8 deg. Otherwise I dont even touch the t-stat. It just stays 68 deg in the house all the time.

I have not noticed any change in fuel usage.

I always figure that if you lower the temp, you will have to regain it by making the furnace run longer to catch up. So the savings are minimal.

[home owner]

As Retired suggested, I followed the "Factory Reset" instructions enumerate d at

Factory Reset: Move Program switch to Set Hold Next to enter setup Press Next to go to step 2 (?Cy?) Press and hold Next until all icons appear Press and hold Next until ?Fd? appears. Press Next three times Move the Program switch

[home owner]

Oren, A factory reset did NOT work

[Bud]

Thats simple. Touch and hold the 2 wires together and the furnace should start/run. Separate them, and it should shut off.

Remember, a t-stat is nothing but a switch (to the furnace). It's just a switch that turns on and off by the temperature around it.

[Ed Pawlowski]

The optimal depends on the degree setback and how long. Too low for a short time does not make up for the catch up. There have been many studies but some info here.

Wr set back because it is more comfortable sleeping in a cooler room. Programmable allows us to set the heat to come on 15 minutes before wake up time.

[trader_4]

From that I would not conclude that the wiring was OK. I'd say it's probably OK, but it could still be faulty. If there is a bad connection, a failing transformer, for example, it might intermittently turn on.

Again, many of us have now suggested connecting the heat wires directly and seeing if the furnace turns on. Or measuring the voltage, see if you have ~24V there.

Most likely it's the thermostat, but until you perform the simple test or get a new thermostat, you won't know. How much more do you want to screw with this? You can buy a new thermostat and if doesn't solve it, take it back.

[home owner]

I've ordered a new thermostat

[Bud]

Good idea. You must be really cold by now, unless you are touching the wires together every hour or so.....

[Ted]

What brand and model did you order?