Furnace Control Board Fuse Keeps Blowing

If the fuse keeps popping in your air conditioner you have a 24 volt short.

Furnace control board fuse keeps blowing.

I am guessing that you are referring to the fuse on your control board is blowing and not the high voltage fuse blowing. The coil in the contractor is 24v. Make sure you have a good fuse and then reattach them one at a time. The contractor may be hanging up or shorting.

Most of the time low voltage shorts are in the thermostat wires. If it is a low voltage fuse problem then you have a low voltage short somewhere. Im going to show you how to fix this problem with just a screwdriver and maybe 5 3 amp fuses and we will fix the 3 amp short im just making this video for my. When your furnace keeps blowing a fuse you need to take action quickly.

It isn t the hsi inducer or blower motor as these are all high voltage parts not low voltage. Fuse on the circuit board blowing in your case you likely have a dead short somewhere in the wiring or a bad load that is going short to ground causing the fuse to blow. Furthermore i would remove all the control wires from the board. If the fuse blows when you have no low voltage wires hooked to the furnace then you have an internal problem like a bad limit gas valve connection or control board.

Assuming this is a fuse on the low voltage side coming off the 24 volt transformer it s possible the contactor in your condensing unit has shorted out causing it to blow the fuse. Here s how to diagnose a low voltage short. Replacing the fuse or resetting the breaker can temporarily fix the problem but if the underlying issue is not fixed the fuse will just blow again. Amperage draw anything near the fuse rating would periodically blow a fuse.

But for those who ve recently encountered one common issue a furnace blowing its fuse before scheduling that tune up it may be due to one or more of the following reasons. If you haven t been diligent about maintaining your furnace all its parts will have been silently and steadily collecting debris and dust. If your furnace is blowing a fuse repeatedly leaving you with no power to the furnace your first step should be to call in an experienced hvac repair professional. Or just throw parts at it.

4 points 3 years ago.