Daikin VRV won't heat

[mike smith]

Hi i am having a problem on a daikin REYQ10PY1B, the unit initially had lost refrigerant so we attended to carry out a full leak check, repair and recharge to the correct amount, this lasted 1 day, we went back to site where we found the unit not heating but the condenser running, the inverter was ramping up and down and the fixed speed was also coming on, there are 8 indoor units with there own BS boxes and all are doing the same, the controller says that we have 55 degrees going to each unit but only 23 degrees coming off (room temp), the pressures seem ok also, can anyone shed any light on this please

[The Viking]

Need more information than that I'm afraid, a lot more information.

In cases like this the Service Checker is an invaluable tool, you just can't beat seeing what the system itself think is happening.

But to start with, what are your pressures? Discharge temperature 100mm from the compressor? Discharge temp leaving the outdoor unit? Liquid line temperature coming from the indoor units? Air ON/air OFF each indoor unit?
Does it work better with just a couple of the indoor units trying to heat? What diversity factor is the system operating with?

Questions, questions, questions...

[install monkey]

did you drive the valves open (via setting modes on the outdoor unit) when relaim,pressure test and vaccing?