I have central heat and air. When the thermostat reaches the desired temp and the blower shuts off the heating elements are are still on and hot and will not turn off unless I shut it off at the breaker. Also when I switch the thermostat from heating to cooling and turn on the air conditioner, the heater elements will also turn on.

Sounds like a defective/stuck on heat sequencer or heat relay.

The central air works on the furnace thermostat but the heat setting does not.what is wrong with my unit?