Furnace blowers continues to run after reaching temp

Sounds like the heat anticipator in your thermostat is either bad or out of adjustment. Turn of the furnace power. Remove the thermostat wires from the thermostat. Turn the power back on. Connect the white and red wires together. The furnace should start up. Let it run a couple of minutes. Then disconnect the wires. The burners should shut off immediately. The blower will continue to run for 60 to 360 seconds then shut off. If this happens replace your thermostat. If the burners continue to burn, then your problem is either the furnace or the thermostat wires.

All York/JCI thermostats made by Venstar

The setup is probably incomplete. Did you configure the thermostat for a 2 stage heat pump? The heat pump should have a thermostat wire connected to R, C, Y1, Y2, and O, that makes 5 wires. I suspect you are only using first stage compression and or first stage blower speed.

You have a high temp safety open. The control board sends a signal through all safeties first. And if there is a safety open, the board believes the unit is overheating, so it engages the blower to cool it down. The safeties are normally on the blower assembly, near the burners, and near the heat exchanger. Hope this helps!

Fan control could be on summer switch. or af control not working keeping fun running

It sounds as if the furnace is working properly. The thermostat is not calibrated.
It is cold here and my heat runs a lot. If you can live with the numbers being off then don't worry about it.

Sounds like it could be your fan limit switch. Part costs about 20 bucks and is fairly simple to replace. This limit switch is a safety that prevents your furnace from over heating. Usually when your t/s is satisfied the blower runs for a little longer after the burners have stopped, and the reason for that is the limit switch. The blower is supposed to cool this limit switch to a certain temp. and once it reaches this temp it shuts the blower off. Yours is stuck:(


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hi check out the temp rise and fall on the fan control see if he has left the blower in the summer swich postion where it runs all the time

Check for a short in the red and white wires.

When the thermostat calls for heat it should run until the room reaches the temperature setting then shut off. Is the blower motor running and can you feel air coming out of the vents? It sounds like the blower is either not running or putting out enough air to keep the furnace heating. The blower moves the heat from the heat exchanger to the room, if it can't remove enough heat from the heat exchanger there is a limit switch that will shut the burner off if it gets to hot and that's what it sounds like is happening.