I have a mitz city multi system that was under performing. I decanted the gas (30kg) - and found that it was about 1kg short of the initial charge. I carried out a leak test and found a small leak on a flare nut.

I know that R407c is a composite of 3 gases and in theory you don't know what gases you have lost. But given that r407c is currently 36 kg - I'm temped to put the original charge + 1kg of new gas back in.

Would I just be wasting my time doing this - and should I opt for a new virgin charge or is it worth a try?