View Full Version : Mini split not communicating with outside unit

26-03-2017, 08:08 PM
Hey guys I'm new to this site thanks for any help. I'm installing a mini split heat pump system. I'm having a problem. The outside unit indicates that it is not communicating with the inside unit therefore the compressor will not come on. On the inside unit it powers up and the fan is blowing. When I test The voltage on the third wire which is the communication wire. In DC voltage it has a reverse polarity of -20 to -30 V DC. I am assuming your first voltage is the reason that's not communicating with the outside unit. Does anyone know what could be causing this how I can correct it?

The Viking
26-03-2017, 08:29 PM
Make and model so that we know what you are looking at would be nice...

monkey spanners
27-03-2017, 07:35 PM
Is it fed from the correct mains voltage?