Originally posted by fat eddy
OK, Here is your answer and it is the correct one. You have a restricted system probably at or very near to the metering device...

They already replaced the accurater with a TXV, then cranked it wide open.

You could spend some time trying to resolve it but what you really need is a good repairman to get a look at it.
This is the correct answer.

This guy is in one of the biggest cities in Australia.

Last I heard, Australia has goods AND services available.

He needs to

1) pick up the phonebook
2) Look under "contractors, HVAC"
2) pick up the phone
3) pick up his checkbook
4) Write the check

Problem solved.