Question about LG LP120HED Wall/Window Air Conditioner

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LG PTAC acting strange in heat mode

I have a new LG PTAC heat pump, LP120HED-Y8. I also installed the optional wireless remote thermostat, PYRCUCCOA. During cooling mode it worked great, now that it has cooled and I am needing the heat, it is acting very strange. It has two stages of heat, compressor and heat strips. Upon setting the thermostat at a higher temp, engaging the second stage it heats great. When it reaches near the room setting it then activates the compressor, then it shuts down. Then when it calls for heat the next time it appears to be trying to defrost. This is what happens:
1. unit turns on normally, compressor running and fans running and heat is coming out.
2. after about 45 seconds the unit shuts off.
3. about three minutes later, the compressor turns on, neither fan running. the system is then in cooling mode as inside coil is cold.
4. runs in this manner for several minutes, then the compressor shuts down, and the outside fan turns on and runs for a few minutes. Then it shuts off, and you can hear the reverse valve shift, and then the unit turns on, heating as if nothing is wrong.
It does this almost every time it calls for heat and takes approximately 12 minutes to start heating. The remote thermostat is activated by one of the DIP switches on the control board, so I can turn it to the position where it uses the onboard thermostat, and it heats normally so my problem lies in the remote thermostat, board, or how I have it set up. The instructions that came with the stat were horrible.
I have called into LG twice, and haven't yet been able to speak to a tech who is familiar with this system. Anyone heard of this problem, or know how these systems are supposed to work, and mostly what the proper settings in the touch screen thermostat are that might cause this?

Thanks so much,

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I believe the problem in lies in the dual stage heat mode setup on the thermostat, but the unit going into defrost does make the unit act kinda strange. Even more so than other types of equipment. I would suggest hiring a licensed HVAC service technician if the problem cannot be resolved by yourself.

Posted on Jun 05, 2009


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