Daikin VRV REYQ14PY1 F3 Fault

[HVACRSA]

Good day all

Having some issues diagnosing a Daikin VRV REYQ14PY1. Not to familiar with VRV systems so please go easy on me

Simple VRV with 2 indoor units 3 pipe system. Recently started getting F3 faults on heating mode. Found Comp 2 extremely warm and cut out on thermal protection. Comp 1 appears to be running great.
Allowed system to cool down for 24hrs. Started the unit up on cooling mode and found Comp 2 not getting warm but slight frosting on suction lines.
Run again on Heating mode and the after 10min Suction line starts getting warm at Comp 2, Comp 1 appears ok.
Daikin advised possible refrigerant shortage, reclaimed refrigerant, 17.4kg of 20.4kg in system.

So my question, would 3kg of refrigerant cause this type of issue? My thoughts would have been faulty 4 way valve or check valve in system. Nearly impossible to see anything in system due to pipework and PCB's.

[Brian_UK]

Yes, shortage of refrigerant can/will throw up faults or cause odd running conditions.