Hi. I am strugggggling to find the answer to this problem.
R22 ducted reverse cycle - york unit
Inefficient cooling is the issue.
Rated amp draw 16.5a - single phase unit
Amp draw is currently 17.5a
Compressor has been wired DOL (start cap/relay removed and just runs off run cap), power to comp is correct and capacitor is ok.
Ductwork, indoor and outdoor fans power, capacitors, coils and airflows are ok.
Plenty of space around the outdoor coil and return air duct is not collapsed and r/a filter is clean.
On cooling:
Outdoor coil on 25 degrees C
Outdoor coil off 39 " "
Indoor coil on 25 " "
Indoor coil off 19 " "
Suction pressure kpa 475
Discharge pressure kpa 1600
Superheat 21k
Subcool 8k
Fixed oriface accurator style LRCD
Unit is heat and cool

Yet sometimes when i equalise unit (when off) through gauge manifold, when the ynit starts back up the suction pressure drops down to 300kpa (after back running for a few mins) and everything else remains similar except super heat goes up by 10 degrees C.

Surely couldnt be short of gas because if i add gas head pressure and amp draw will increase further.
Suspected possible faulty comp or rv but head pressure is a tad high rather than low and amp draw is quite high not low. Unit has an oil return and suction accumulator. But if oil return was leaky discharge would be slightly down? + the temps across either side of the solenoid are the same temp.
No idea of unit history as they are new to the home.

Anyone got any ideas? :/