Why does my new house thermostat not cool?
Sunday, January 31st, 2010 at
12:39 pm
I just replaced my old thermostat to a digital one. Everything seems to be working but it just doesnt cool. Air comes out but its not cool. I walk outside and the outside unit is running along with the inside unit. I think i have a 1heat/1 cool heat pump system.! help!!
I reinstalled the old one and everything works perfect again. It cools with the old one.
The manu. is Honeywell. I have a jumper from W to Y.
Filed under: Wind Power
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Since you reinstalled the old one and it works fine, it obviously is not the proper thermostat or it is defective out of the box.
I question the jumper from W to Y as W is commonly a heat connection and Y is a cooling connection. I can’t think of a reason to jump the two of them out.
If you reinstall the new thermostat, leave the jumper off and see if it works.
Hope this helps
If the outside compressor is running and the inside fan is working properly, then the most likely reason you’re not getting cool air is that you are out of refrigerant. The system could have a leak, or a line might have gotten punctured. Sorry, but it’s time to call a repair service.
-Edit-
Heat pumps definitely have refrigerant.
http://highperformancehvac.com/hvac-refrigerant-leak.html
I had the same thing happen last year to me. I called for someone to come out and look at it and they told me that I needed a new thermostat and motherboard. I have a heat pump system also. It does not have a refrigerant. It heats in the winter and cools in the summer. The furnace really doesn’t kick on until it gets below thirty and it saves me money.
It just stopped working yesterday again and now it doesn’t run and I have someone coming out this afternoon.
Last year, I went with a local company and they also told me I would need heat sequencers which I do not have and that particular person told me I would not have heat until I got them. He had replaced the motherboard and thermostat at that time. When it got around 30, I had no heat, so I called someone else. The second guy asked me why my wires were disconnected. I had no heat sequencers. All the guy did was reconnect the wires and it worked. I questioned whether or not I needed the motherboard or thermostat.
They sent me the money back for the second guy. I would make sure you ask around when you do have someone come and look at it. Mine is 9 years old. I don’t know how old they are when they go out.
Just to give you what happened to me and hopefully my experience will help you with yours in some way.
A heat pump has a reversing valve that switches the flow of refrigerant depending on if you need heating or cooling. If the valve is energized during cooling, there should be a wire that will go to the ‘O’ terminal on your thermostat. If the valve energizes in heating a wire will go to the ‘B’ terminal on your thermostat. Depending on the manufacturer of the stat, there may be a jumper on the board to set for heat pump operation, it may need to be programmed in the key pad, or you may have to install a jumper on the wiring terminals. If you can provide the manufacturer and model of the thermostat, that would help. Otherwise, carefully follow the instructions in the manual. Wiring a heat pump is a little different than wiring a normal A/C system.
The ‘W’ terminal is the heating terminal on a normal furnace, the ‘Y’ terminal is the terminal that will operate the compressor. It looks as if the compressor will run in heat or cool but the reversing valve isn’t being energized. If you can tell me the terminal designations and wire colors on your old stat, and give me the model # of your new stat, I might be able to help you out.