Blower will not shut off

This could be due to either an open safety switch such as a rollout or high limit, or the relay could be welded inside the control board constantly sending 120 volts to the blower motor. A less common cause could be a bad thermostat which can be verified by removing the face plate. If the blower stops, then the thermostat will need to be replaced.

When you set your thermostat to auto, it will automatically shut off when it reaches the temperature you set it at. I personally set mine on auto because I don’t want it to run constantly. This will save you money on your gas or electric bill. The blower will run constantly if you set your thermostat in the on position.

There is a relay that controls that fan. They are not cheap. IT is most likely frozen.

Check the thermostat and make sure the fan switch is set on "Auto". If it is set on "ON" the blower will run constantly.

fan relay stuck in.

It could be a thermostat problem. Also it will seem to run constantly as it tries to heat and one of the elements are working which could be a sequencer problem.

Is there a setting on the thermostat for Auto or Fan? If so, make sure it is in the Auto setting. You will have a contactor that turns on the elements and a relay for the fan. Follow the wiring diagram to see which relay energizes the fan then unplug it to see if the fan stops.

hi! there,
blower auto shutting off and on is dependent to thermostat setting,if the thermostat acquired the temperature set it will shut of your blower,checking thermostat performance switch off unit, set this to a lower setting 1 or 0 switch on this should not runof course,if you set up this to 200 this will run until temperature reached to 200 it will stop.when you set up to 1 or 0 and the blower run thermostat is defective.
fan blower relay, if the 3 contactor is short or permanently engage while themostat reached acquired temperature your blower will still running,defenitely relay is defective.relay is dependent to thermostat switching,it supply holding coil terminal is to lock the 3 contactor to supply source to your blower.
so two common option while your blower run continously
1. shut off breaker, disconnect thermostat on two leads,its like a switch.then switch on breaker and run unit.
observe if run, your relay is defective,it was shorted on 3 contactor.
thermostat is the key to run your blower.
2. if the blower not run when you switchn onunit,then switch off again and try to short or connect the two lead using alligator clip on both side,or have it clip the terminals,then switch on again if the blower run,your themostat is defective,the high volatile of filler bulb was leak it always switch on,no play at all to off and on.
have a nice day,don't forget to rate me,thank's
ideas came from actual and theoritical analysis base on experienced and my study of industrial intrumentation.this will guide you and help you,if you understant flow of current in circuit.
have a nice day

Try national energy they are on line and carry most spares