VRV II intermittent High Pressure fault, Board issue?

Hi Guys,

Getting an intermittent E3 faults on a REYQ14M VRVII and could do with some help!

According to the customer the following works have occurred:
Daikin attended site, said air was short cycling and solenoid valve needed replacing.
Fan motor & valve fitted and unit appeared ok during winter (heating)

fault reoccured, unit placed on monitoring system, never reached HP, intermittent fault.

All 3hp switches and hp transducer fitted.

and then my visit. I watched the unit run, sometimes it would be approx 30 secs into startup, other times it would run 5-25mins.

I checked continuity and voltage across all Hp switches, and checked the gauge pressure on the compressor discharge right next to the transducer, compared it with the voltage/pressure on the transducer and it was spot on. The highest I saw it trip was 24bar. A call to Daikin and they inform me it's the board, made sense to me.

I suggested swapping one out from another on site to confirm this, tried and it wouldn't start and gave a few different codes out, valve fault, high pressure. I then swapped the boards back to investigate the valves further. Long and short of it is I now have two units showing the valve fault (which I can't seem to clear) and an unhappy customer!

Anyone experienced something similar?

Thanks for for your time

Did you carry out a system reset after swapping the PCB?

Whenever you change the PCB you need to carry out the reset. Turn the power off, hold the reset button down and then turn on the power. Continue to hold reset button until you hear a click, then release the button. System will then go through its initiation and hopefully the fault codes will disappear.

What was the model number of the outdoor unit you took the PCB from? This will give you issues if the HP doesn't match and like the others have stated, you'll have to reset the PCB so it can search for the correct number of BS and IND fan coils.