Furnace Relay Switch Problem

First make sure your furnace power is turned.

Furnace relay switch problem.

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. Verify the furnace door is closed fully as an open door will cause the furnace not to work. Turn off the furnace at. If the fan limit switch worked normally continue as follows.

Move the lever on. Then turn the ac back on to test it. If it works for the next 12 hours you ve solved the problem. Furnaces require electricity to operate oil pumps thermostats internal electrodes relays and other electrical components.

With the furnace on use a. Many times wires are either loose or burnt behind the fan center relay. 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. Check the emergency switch usually located near the furnace room.

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 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.

You may have to check a few areas to eliminate this as a problem. Make sure that your furnace switch is on the furnace blower compartment door is on and secure. Check the main circuit breaker entrance panels and any fuses or circuits found in the furnace itself. 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.