"Desperate" MHI inverter wall mounts not heating .

[Birds]

Good evening

Desperate for some advice.
We have just installed 14 splits at an exhibition in Barcelona in hotel at the moment.
We always use flexible pipes and have no problems when used in cooling. Today we have had a number of MHI units operating in heating, nice and hot. but during today a number of these units have stopped heating and have the flashing run light on.Compressors running but no heat at all. recovered 410A and weighed in factory charge was short by 300gm.Put into cooling and watched gauge go down to zero and stayed there, as if pumping down.The model is SRK 50 ZJX-S

Any help or advice would be appreciated.

Thanks

[install monkey]

moisture blocking the drier? check for a difference in temp between the inlet/outlet

[Tayters]

Not a 6 wire EEV head faulty?

[croc1774]

flexible pipe bent on return !