Hello chaps,

I have been working on a reyq16mw1b r410a system today, which another company have already worked on and left in a abit of a state, they replaced inverter pcb and inverter compressor.

It had a leak which I repaired and recharged correctly.

I found EEVs (3 altogether) connected incorrectly which I have put back, I then checked all valve operations with a magnet and solnoid resistances and operation, all ok.
There are 2 X large green solnoid coils, 1 discharge gas and 1 suction gas, which when operation in heating is preformed sometimes the discharge gas solnoid energises and sometimes doesn't not, when it does not it goes out on HP, I have checked voltage from the board and it is not trying to power the solnoid, does anyone know what tells this valve to open or is it just when it's in heating.

I have also tried the tap the relay on the top trick... No luck

Next the sub 4 way valve solnoid does also not energise at all therefore always sending hot gas to sub coil, again no power out from the board to energise coil at what point should this coil energise.

after telling Daikin all this they are saying fault with main pcb, which at this time I agree.

To prove system actually runs, I ran full heating (when discharge gas solnoid decides to energise) and put a magnet on the sub 4 way valve, which was all ok.

I then ran full cooling which was also ok.

Anyone think differently to main Pcb?

I appreciate any feedback.

Thanks
Glenn