Furnace Relay Switch Problem

A switch inside the door compartment engages when the door is closed properly.

Furnace relay switch problem.

Then turn the ac back on to test it. Make sure that your furnace switch is on the furnace blower compartment door is on and secure. First make sure your furnace power is turned. Turn off electrical power to the heating system reconnect the fan motor where you previously disconnected it turn on electrical power to the heating system call for heat.

Furnaces require electricity to operate oil pumps thermostats internal electrodes relays and other electrical components. Verify the furnace door is closed fully as an open door will cause the furnace not to work. Check the main circuit breaker entrance panels and any fuses or circuits found in the furnace itself. Move the thermostat mode switch from cooling to off and move the fan switch from auto to on let the blower run for at least 30 minutes or until there s good airflow at the registers.

That is definitely one possibility. Set the building thermostat to call for heat. The reason for this is that the relay could become welded into the closed position and continues to allow power through to the heating elements and the fans. If the fan limit switch worked normally continue as follows.

But another problem that occurs just as frequently from a faulty relay is that the heating elements and the blower fan will refuse to shut off. Move the lever on. If this isn t the problem you can reset the power by switching the furnace off at the furnace power switch for about a minute. Switch it back on and see if this corrects the problem.

Furnace blower fan wont turn off fan select switch on the thermostat is in the manual on position a control wiring problem where the insulation on the wiring is worn off a bad relay fan sequencer relay fan limit control or circuit board with contacts sticking this depends on the type. You may have to check a few areas to eliminate this as a problem. If it works for the next 12 hours you ve solved the problem. With the furnace on use a.