Furnace is not working after changing thermostat

possible stat failure

Sounds like tstat issues. Turn power off, take pictures of wiring, replace stat, turn power on. Good Luck!!

If you need further help, reach me via phone at https://www.6ya.com/expert/thomas_092728000e6acb79

Some thermostats allow you to change the differential value - that is how far below the heating (or above the cooling) set point before calling for heat (or cooling in the case of air conditioning). The built in 1 degree differential setting provides the most even temperature in the space at the expense of more frequent furnace firing and stopping. Many people prefer this mode as opposed to allowing wider swings in temperature for less frequent furnace firing and stopping. If you wish to change this setting, you'll need to replace the thermostat as it is not user adjustable in this model.

I'm thinking the heat blinking means its calling for heat and its not completed the Rh to W1 circuit yet. Once the circuit closes, the blinking heat will go steady....usually. Or if the thermostat is satisfied, it will stay steady and not blink...

I guess your thermostat could blink whether its mode is satisfied or not because I am not familiar with that particular stat. You forgot to say if the furnace is gas or electric heat, so if its gas, it sounds like it could have misfired and locked itself out. Go to the furnace, and cycle the power switch that should be mounted on the side. This will reset the controller and give it another attempt at firing correctly. If it continues to lock our after several attempts and you still have no heat, you have no choice but to call for service.

If its an electric furnace, there isn't much you can do but call a technician for a service call.

From what you learned from your neighbor, I would say no. Certainly, sounds like a manufacturing defect to me.

Since it's within 2 degrees of your setting it could be one of two things. Most furnaces run longer (pass your setting) to maintain the setting you made. Which really not a problem. However, your thermostat may need calibrating. To test this theory, place a regular wall thermometer next to your furnace's thermostat and see if the two temps match when the furnace cuts on and then when it cuts off.
If the temps are both the same, the furnace thermostat is fine.

If you're turning it down to 68, because no one will be at home during the day, just set it 2 degrees cooler than 68 degrees. You will then wind up with 68 degrees.

You can make sure it is not the thermostat by crossing or jumping the R and W terminals (or associated wires) together. This will keep the furnace calling for heat. As it is approaching set temperature, get in front of the furnace and inspect the air filter to make sure it is clean, watch the control module for any error codes that may be turning off the system prematurely.

On a call for heat, the 24 volt thermostat sends a signal to the control module. The control module will indicate a call for heat with a light on the control either blinking or remain solid depending upon model. The inducer (exhaust) blower will purge all gasses from the furnace and pressurize a pressure switch. Once the pressure switch tells the module to continue, the electronic ignition will energize and send 120 volts to the igniter. The igniter will glow and you will be able to see it if viewed thru the small inspection port. Once the igniter gets hot enough, it sends a signal to the module opening up the gas valve (24 volts). Either a pilot will come on or the burner tube will ignite then spread the flame to all burners. Lastly a safety sensor will be looking for a certain temperature within a few seconds and the furnace will continue to operate and the room air blower will turn on in a minute or two.

What could go wrong? The unit will not run if there is no signal from the thermostat (bad thermostat or broken wire), the control module does not sense a signal from the thermostat (bad control), the inducer does not energize (bad motor), the pressure switch does not close (blocked vent piping, bad switch, plugged condensate hose), the igniter does not energize (bad control, bad igniter), the gas valve does not open or there is no gas (bad gas valve, broken wire, no gas), the pilot does not light (dirty pilot), the burner does not light (bad burner, plugged orifice, not enough combustion air), the flame does not spread to each burner (bad flame spreader, dirty flame spreader, more bad burners), the flame safety sensor does not detect flame (dirty or bad flame spreader, bad flame sensor, broken wire, bad control), or the room air blower does not energize (bad fan motor, bad control).

Tjere is a limit switch that will only allow the durnace to reach a certain temp by kicking on the fan. The thermostat being unable to read the temp affects its ability to keep the furnace from exceeding your settings. *Advise not to use until corrected. Both limit switch and thermostats are inexpensive and simple to change. If in doubt, call a heat and AC tech to repair.

Joss sounds like the anticipator setting on thermostat i would replace it with a digital it will be more actturat . The furnace has to go over temp setting to turn off

the power to your furnace has been turn off. check the switch at the top of the stairs.