Furnace Control Board Has No Power

If so it will need to be replaced.

Furnace control board has no power.

What would cause electric furnace circuit board to fail. Just went thru the flow charts from rheem on that furnace. Heat mode goes strait to trouble code bad ground open ignition circuit also no power from board to induction motor. A model number of the furnace would be helpful too.

It is possible that the problem could stem from your electrical system rather than the furnace itself but your hvac system is the best place to start. Make sure the 110v power switch at the air handler furnace has not been turned off then see if the fuse on the board at the air handler is not blown automotive type then there is a safety switch. Next you want to check the output and this is a little more involved than the previous step. You should see 24vac.

Fan only operation is running. Measure from r to w. Power up transformer cool mode works blower stays on after temp is reached. Either way check to make sure you have the proper input voltage to the board.

Check for 24 volts to board from transformer. The ac power is disconnected. The electric furnace transformer may be failing causing the system to short. You have bad board replace it.

You should see 24vac. With the stat in off mode. If you have 24 volts and no light on board. Don t forget when the blower door is open.

Furnace control board fuse keeps blowing 1 answers hi i have a carrier furnace 48gs 036090311tp with a honeywell t8401c thermostat. If your electric furnace is blowing a fuse repeatedly when turning on your first step should be to call in an experienced hvac repair professional. If your building s electrical system supports 120 volts your furnace needs a transformer to convert to the correct voltage to run the controls ignition and timers. In some cases this will be line voltage and in other cases the board will get its power from the control transformer.

First make sure you have power to the board. I can run the fan on continuously but when i put the heat to on on the t stat the 5 amp fuse on the control board lh33wp003a in the furnace blows.