While I was replacing old Honeywell 7day programmable thermostat with new Ritetemp touch-screen programmable thermostat, something went wrong and now I have no fan nor heat. The phone support at ritetemp suggested that I must have blown fuse of the transformer.

I have 12yrs old York Heatpump model 2HM06501306D. Inside the unit of the indoor unit looks simple and wonder if I can replace it easily.

Any suggestions will be greatly appreciated.

First check for a fuse. It is quite common to have an automotive style blade fuse on the circuit board where the thermostat wires go. Also verify the unit is getting power from the house. Look for a separate transformer. The circuit board is much easier replace than pay for. If you must replace the board, it isn't rocket science. Putting the red wire on the terminal marked R is easy. You may want to not the blue wire is on the com not B. Many of the other wires will be on one big plug. Careful note where any others are. Before I replaced a board with a bad transformer, I would study just replacing the transformer.

First check for a fuse. It is quite common to have an automotive style blade fuse on the circuit board where the thermostat wires go. Also verify the unit is getting power from the house. Look for a separate transformer. The circuit board is much easier replace than pay for. If you must replace the board, it isn't rocket science. Putting the red wire on the terminal marked R is easy. you may want to not the blue wire is on the com not B. Many of the other wires will be on one big plug. Careful note where any others are. Before I replaced a board with a bad transformer, I would study just replacing the transformer.

Hi, Thanks for your note.

The unit circuit board has 2 switches and one of them doesn't make humm sound. Doesn't the fuse sit inside of the switch on the circuit board? But I don't know how to remove the plastic cover which sits on the two switches. Should I pull it hard or is there a hook that keep it in place? I don't want to break the plastic.

The fuse may be separate from the switches. The switches could also be circuit breakers. Once you pull hard enough on the plastic covers to break them, you will be able to see where you should have pried or squeezed to remove them. Try to see where the most resistance is and push in on the cover at that point. Once you have the cover off, try turning the switch all the way to off, and then back on.

The fuse may be separate from the switches. The switches could also be circuit breakers. Once you pull hard enough on the plastic covers to break them, you will be able to see where you should have pried or squeezed to remove them. Try to see where the most resistance is and push in on the cover at that point. Once you have the cover off, try turning the switch all the way to off, and then back on.

I gave up finding a fuse. But before I completely give up, I would like to make sure that the wiring on my thermostat wasn't causing the trouble. If the green wire (for fan) is in the right place where marked green, doesn't at least the fan shoud come on even if any other wire is connected to wrong place?

Thanks.

Nothing will happen without the red wire connected to the RH terminal, and maybe the RC too for the fan. You can remove the thermostat as a possibility by jumpering the R terminal at the furnace to the W or G. If nothing happens, it is back to finding out why you don't have the 24 volt control voltage.

Nothing will happen without the red wire connected to the RH terminal, and maybe the RC too for the fan. You can remove the thermostat as a possibility by jumpering the R terminal at the furnace to the W or G. If nothing happens, it is back to finding out why you don't have the 24 volt control voltage.

Thank you for following up my question. My problem was I tripped off the electricity to the heat unit. The Fan didn't come on any longer. I was told to replace a fuse at the electric box where transformer is located. I couldn't find the fuse. So finally I called a heat-man and within a second he pushed a little reset button underneath the 24VC circuit board area and bingo, everything came back. I paid $80 for this hidden reset button and a lesson.:(

Possibly if I explained you better, you could have given me about the existence of reset button and its location.? :rolleyes:

Thanks again.