Its just being used for cooling right now.
Furnace control board fuse.
Every troubleshooting tip i found said to disconnect the w heat relay and r 24v supply terminals from the thermostat and jumper them on the control board.
This will blow the fuse on the control board causing the draft inducer to not start which then stops the rest of the furnace functions from working properly.
I replaced the original control board with a honeywell st9120u1011 universal control board about two years ago after the original one blew.
The guy has a new condensing unit installed last year.
Here s how to diagnose a low voltage short.
Furnace or ac control board troubleshooting.
Should i check amp draw on compressor and both fan motors.
If the fuse keeps popping in your air conditioner you have a 24 volt short.
Electric furnace thermostat control wire.
Can you guys point me in right direction to figure this one out.
He just called and told me fuse is blown again.
When a valve is unable to open and close properly it can sometimes heat up causing an electrical short that blows a fuse.
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.
Electric furnace problems can be frustrating especially when they come at the worst time.
I removed all the wires going to my thermostat and it would not blow the fuse when powered on.
Your furnace s control board has a separate fuse that protects it from getting too hot.
Diyers often try and handle things on their own.
If someone pokes around your furnace and isn t careful they may loosen wires from the furnace s wire frame causing them to short and blow a fuse on the control board.
I turned off the input power and attached terminal r 24 vac power to thermostat and the fuse blew.
I was blowing the 5 amp fuse on the control board for my forced air gas furnace.
I did a recent service call and the 5 amp fuse in the circuit board on the furnace was blown.
Is your air conditioner or furnace not turning on or p.
It isn t the hsi inducer or blower motor as these are all high voltage parts not low voltage.
Cartridge fuse flat blade dual element time delay class rk5 250vac 125vdc 200a 7 1 8 l 1 9 16 dia.
If you have a gas furnace one of the valves may be failing.
My furnace is a concord model cg90ub.