Thermostat Keeps turning the HVAC on and off

My thermostat turns the furnace on, runs for few minutes and turns off. Turns it back up again in another few minutes and this keeps repeating. It doesn’t let it run long enough to heat the home and the temp is 4 deg below the set temperature. Any help would be appreciated.

are u 100% sure it’s wired correctly? can u post b4 & after pix?

Well, I’m pretty sure as it was working fine until a couple days ago.

Is there a vent that is blowing on the thermostat? What sort of system do you have: Gas/electric/heatpump/oil/other.


No, there’s nothing blowing on it. As you can see, it registers that the temp is low but it never lets the furnace run long enough to bring it up. This is a gas furnace.

Is it turning off the gas furnace, or is the gas furnace tripping on something like a flame sensor/ rollout/ pressure drop? The fact that it thinks it is going to take 47 minutes leads me to think that you might have a furnace issue.

I thought about that as well, but I can clearly hear thermostat relay click to turn the flame off after a few minutes.

Put your old Thermostat back and see.

Also, rapid cycling kills your HSI.

Yes, I didn’t have time, but I’m going to do that today or tomorrow. I’m worried that something might break due to the constant restarts.

Post the make model number of your furnace, pic of the board. Wire Terminals and pic of Tstat wiring.

Have you watched the furnace when it is running to verify that the flames look good?
If your furnace’s safeties are tripping, they can cut power to the thermostat until the fault resolves itself- this points to a possible bad high limit or rollout switch. This would also cut power to the wyze, causing it to click like you are hearing. Does the entire thermostat reset when it turns off?

No. Thermostat does not reset. It turns the furnace off.

If your old thermostat was working fine its not the furnace its the wyze thermostat, I’m having similar problems as well. Everything worked fine before I’m working with wyze on my issue I recommend you do the same. The issue I’m dealing with is sometimes the fan doesn’t shut off, and other times it won’t start even when it is below set temp, You can shut the unit down or even remove it from the wall to reset it I had to do that several time to get it to the set temp. I think there is a glitch in some of the units.

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Wanted to respond to this question and share my experience on how I solved a similar problem I had experienced - mine being the heating was getting turned off way before the desired higher temperature was reached and the furnace just kept blowing cold air since the heating flames in the furnace had shutoff.
To test if it was my Wyze thermostat that was at fault I did a wire bypass between the R and W wires after removing the face plate. The bypass method turned on the furnace and did not turn off the heating until I actually removed the wire bypass after a prolonged period of time. (Just search Youtube for “thermostat bypass” in case you don’t know what this is, which is basically connecting by a conducting wire the R ( power) and W ( heating) wires or pins.
Wyze support recommended one solution was doing the factory reset of the thermostat. I did just that and it fixed the problem. Factory reset how- to videos can also be found on Youtube.