Hi,


I am a refrigeration engineer for drinks systems / milkshake machines etc. but now work in the office on IT and technical.

About 2 years ago we had 2 split ceiling grid mounted air source heat pumps fitted with a PAR-F27 or similar controller. I don't have the exact model of controller handy but I can get it if required.

Despite calling the installer back they seem unable to solve a problem. It had been a bit tricky to understand but I have the hang of it now.

The temperature in Heat or Auto doesn't read the correct value. When you come in in the morning it will read ok, e.g. 15C. You put it in Auto / Heat and it will heat. Then later on in the day e.g. 11am the office will be too warm. At that point the controller is reading the set point and still heating, e.g. 22C. If you then put it into Cool then then after about 5 seconds the controller then reads the actual room temperature, e.g. 26C and starts to cool spectacularly!
Strangely if you put it back into Heat or Auto it will then read 22C again and start to heat again. The installer was challenged about this but they couldn't really understand the problem and introduced a new problem by programming the controller in some way so now when it is in Heat or Auto it flashes between Heat and StandBy and so when it's really cold e.g. 8C it takes a long time to warm up because it not in full heat.

It would be really helpful if a clever bod here could help me to program the controller correctly and provide kudos to me and them for sorting it out.


Many thanks in advance for any help you can provide.

Spencer.