Trouble with Hitachi splits RAK50PED & RAC50WED

[Makeit go Right]

Had an engineer install two Hitachi 5kw R32 splits RAK50PED & RAC50WED. Just a straight 5m and 6m run with the flares outside. Quite a simple install..... but when tested with 450psi ofn, both systems were losing pressure (30psi/15psi) in 10mins. Flares checked and rechecked (leak spray) and engineer worked out that service valves were letting by. Both systems!

The distributor (H) is not showing any interest and quite awkward about it, sounding like his responsibility will extend only as far sending a couple of service valves (if lucky) so I can fix the problem this has caused (great).

The kit was on special prices and whilst there is the buy-cheap-buy-twice chime in the background, I had expected more from the Hitachi brand (and that distributor).

Anyone else had issues with service valves letting by?

[Tayters]

Several years back but not so much these days.

[al]

Yes and particularly with Hitachi, there early 410a had a service bulletin issued which if i remember right said we should not subject the service valves to high pressure, ie test pipe work only!

Have never had an issue with any other brand

[bobjob]

I would be interested to know how you have tightened up the flares on the outdoor unit.
Did you have a adjustable spanner holding the shut off valve and another spanner on the flare nut or did you tighten the flare just using the one spanner on the flare nut.

I have sometimes caused the shut off valve to leak refrigerant through when using both spanner’s and now only tighten up the flare to the correct setting using one shifter on the flare nut.
This of would only be on the smaller condensing units up to 5kw 1/4 -3/8 and 1/2 pipes

Regards bob