R22 split system pressures

[ACdiag]

Hi people , i installed an R22 split system a week ago , it has stopped pumping heat .

The system worked fine at day one , plenty of hot air coming off the outdoor unit , indoor temps chilled down nicely to 16 celcius.

after a week of running it is no longer producing the cold stuff inside and the outdoor unit is blowing only ambient air.

i checked all the flared connections and its not showing leaks anywhere.

when first installed i pulled vacuum down to minus 30 and held it for over an hour , it showed zero leakage then.

There is only 2.5 metres of copper , its a pregassed unit that can handle up to 3 meters copper before adding additional gas.

a gauge set on the service port today (low side) shows 140 PSI (0.96 MPa)when the unit is turned off , when powered up it shows only 8 PSI.

spec sheet says only that maximum pressure on the low side is 1.2 MPa and high side 2.8 MPa but doesnt give a minimum figure.

any thoughts on the pressure readings ?

there are no gauge ports on the high pressure side so i cant check that.

[Brian_UK]

Gas leak I would think.

[hyperion]

Definitely sounds short of gas.

[Brian_UK]

I take it that you did not perform a pressure leak test only a vacuum test.

[Keza]

Sounds like a gas leak.
You can't pressure test by vac test.
You have to put positive pressure into the system (dry nitrogen). You could have over tightened a 1/4 flare nut and the unit would hold vac fine but when you released the gas it blew the flare off or it stated to leak.

R22 is very expensive refrigerant due to it being phased out and it depletes the ozone layer.

Another question, why are you installing an R22 unit? In Australia we are not allowed to install any R22 units, only repair.

Good luck,
Keza

[Kev The Tool]

Sounds like a sparky with a split bashers ticket, should'nt be installing R22 unitsin OZ, might be worth asking the customer if they would like a price for a new unit!

[mikeref]

R22 splits were phased out some time ago. It's R410a or R32 these days.

Reckon this A/C will be an old second hand kit. 140 PSI standing pressure is around 25*C, IF there is substantial liquid R22 in the A/C.
At this time of the year, no-where in OZ has an average daytime temperature of 25 C.... 8 PSI suction when running can only mean it's Short Of Gas. :)