The 3A fuse blows on the main board when the bottom door switch is pushed
I have a GMH 951155DX furnace. The heat cycle works okay. When I switch to A/C and push the bottom door switch the 2A fuse on the main board blows. I put a new main board in. I removed the condensor two wires, I removed all the wires and plugged them one at a time, when I plugged the wire into the rollout sensor, it blew the fuse. I get 6 blinks, which says "bad fuse" or "rollout sensor open" I disconnected the wires to the thermostat, hooked them up one at a time, when I hooked the red wire the fuse blew. I replaced the thermostat, no help. This is a new installation, it did work for a while, I had a freon leak, when I repaired that, then the condensor would not come on, that is when I found the fuse blown.
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Re: The 3A fuse blows on the main board when the bottom...
There is definitely a short in the 24volt(low voltage) system. You have done the right things so far. I would begin by physically inspecting the wires for damage and performing continuity checks for each wire as well as each wire to the furnace. These checks should be done with a meter and disconnecting each wire at both ends.
Sometimes there is a very small bare spot touching the furnace or ductwork. You can diagnose this by checking continuity from the wire to the ductwork. If there is continuity then that is your problem.
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do you have the lower door in place tight ?? because there is a door button switch. so if its not pushed in all the way you would have no power at furnace. also make sure nobody turned off the on off service switch usually above furnace or sometimes one at top of stairs and one down by the furnace .if those suggestions don't work you might want to turn each breaker off then back on incase one is tripped. if that don't work check for 120 volt at your fan timer board also it may have a automotive style fuse on the board which if blown it wont do anything. if there is 120 volt at board and the 24 volt circuit fuse is good its probably the fan timer board.
This can be caused be either a short in the wiring, loose connection on the board,or a low voltage connection not secure on the board. Check all connections to make sure they are tight and secure. Let me know what you find.
If the thermal fuse blows it is a direct result of heat. The most common place for the heat to be generated is the wire connections to the fuse, the wire connections on the main control board and the door switch.
The thermal fuse comes with a small wire kit, be sure you or the technician used that wire kit if not you will continue to have trouble. If you have then look the board over closely, especially the black plastic plugs, if you see any dark spots or loose connections make sure to tighten them up. Then check the wires to the door switches make sure they are tight connections. If all these are okay then check the gasket on the left side that surrounds the vent, if heat escapes this gasket it can migrate over toward that thermal fuse.
It doesn't work at allIf your microwave oven doesn't seem to work at all, check these:FusesDoor switchFusesUsually, when your microwave oven doesn't work it all, the internal fuse (thermal fuse) is blown. This fuse protects both you and the oven. When it blows, you need to have a qualified appliance repair technician replace it.Door switchIf the fuse isn't the problem, check the door hooks and the door-release button. When these are broken, the door switch doesn't activate, so the oven can't work.It sounds normal, but there's no heatWhen the microwave sounds okay, but there's no heat, one of the internal door switches, the high voltage circuitry, or the circuit board may have a problem. To resolve this problem, you need the assistance of a qualified appliance repair technician.
THIS IS A COMMON PROBLEM WITH THE DOOR SWITCHES, MY FIRST ANSWER WOULD BE REPLACE THE SWITCH SECOND WOULD BE OPEN THE DOOR AND PUSH THE BUTTON IN AND SEE IF THE FURNACE WILL WORK. THIS SWITCH IS JUST A DOOR SAFTEY IF THIS WORKS. I HAVE TAPED A PIECE ON THE INSIDE OF THE DOOR WHERE THE SWITCH WILL HIT THE DOOR ABOUT A 1/4 INCH THICK AND SEE IF THIS WILL GET YOU RUNNING UNTILL YOU CAN GET A SWITCH
Hi!!! Does your ac unit work fine?If not check your low voltage problem..You have a low voltage problem check the wire going out to your condensor make sure that they are not touching..Good luck..Check low voltage wires..short in progress..
These new furnaces are trouble. Ive been in the htg trade for 25 yrs. The fan is running because they are now controlled by a timer instead of a temperature control. Rather than sensing a preset temperature and turning on the fan, it comes on by a preset time. Couple of things, does either of the doors have an inspection window? most newer furnaces have what is called a smart board. The board will flash a trouble code. ie: 1 long 2 short etc. #1 turn your thermostat to off, youll need 2 people for this! Go to the furnace, If it has the above mentioned inspection window ( usually about 2" round) while peering through the window have someone turn the thermostat to about 80 degrees. Let the furnace cycle and see if it flashes a code. If it does the codes are usually on the bottom door, May be on the inside. The most common cause is either a bad transformer, bad hot surface ignitor or pressure switch failure. Further questions feel free to ask. Steve