Daikin R32 Sky Air RZAG100M7Y1B no compressor start

[knocker]

I am getting an odd issue with 3x RZAG100M7Y1B Sky Air single split systems. When the FCU is set to cooling at 19c set point from the controller. The unit runs, but does not supply any cooling, the compressor never starts and no faults are shown. Indoor thermistor readings Th2 & Th3 are all the same as the return air reading. This also happens in test run.

I have checked the terminal 3 coms line. Disconnected from the indoor and outdoor to check for any interference. I have also checked the terminal 3 voltage from the outdoor unit and found that the voltage alternates between 11v and 52v. These systems have been running with no issues for 18 months.

We have also had the exact same issue just yesterday, but with a RZASG140M7V1B condenser at a different site.

My thoughts are on a defected outdoor PCB

Anyone had the same issue?

Tom

[scoffs]

Had the same issue 4 weeks ago spent 4 hours fault finding only for daikin to say they have issues with cond pcb. Check with daikin most likely still under warranty we had one free of charge.

[R666A]

I am getting an odd issue with 3x RZAG100M7Y1B Sky Air single split systems. When the FCU is set to cooling at 19c set point from the controller. The unit runs, but does not supply any cooling, the compressor never starts and no faults are shown. Indoor thermistor readings Th2 & Th3 are all the same as the return air reading. This also happens in test run.

I have checked the terminal 3 coms line. Disconnected from the indoor and outdoor to check for any interference. I have also checked the terminal 3 voltage from the outdoor unit and found that the voltage alternates between 11v and 52v. These systems have been running with no issues for 18 months.

We have also had the exact same issue just yesterday, but with a RZASG140M7V1B condenser at a different site.

My thoughts are on a defected outdoor PCB

Anyone had the same issue?

Tom

Have you a D-checker? If you do - see the Indoor & Outdoor Unit thermostat's statuses. They must be ON.

[al]

Had same few weeks ago, same oudoor as well i think, replaced outdoor pcb, working fine now.