Air Con not working after service

[plucka99]

Just had my first service done a week ago on my 4 year old ducted aircon. Had been working perfectly. Techinician said the only thing wrong was the coolent level was a bit low and added some more. Initially all seemed fine but I started to slowly notice it taking longer to cool down. Now today the air is not being cooled at all and the big giveway is the outdoor unit (compressor?) is blowing out coolish air instead of hot air as it always has done.
I wondering if this is likely a gas leak seeing it took a week to completely fail. I hope this is a simple mistake they made and not some kind scam to rip me off for extra repairs.

[nike123]

It is probably overcharged now. He was needed to recover refrigerant and weighted it to establish if there is right or wrong quantity of refrigerant in system. Only then he could charge by weight right amount of refrigerant.

[S_Line]

There is a possibility of a leak in the system.
Get him back to have a look.

Tell tale signs of a leak, is oil around outside flare nuts.

Did he say how much refrigerant he added ?

[plucka99]

There is a possibility of a leak in the system.
Get him back to have a look.

Tell tale signs of a leak, is oil around outside flare nuts.

Did he say how much refrigerant he added ?

Where are the flare nuts?

I think he said he added about 1KG. He replaced/fixed some valve where he suspected the leak came from also.

Could the system be damaged if run while out of gas? I imagine it had been running all afternoon before I noticed the problem. Also if I turn the system on again now to seems to work again, initially anyway, I suspect it would fail again but don't want to run it in case I cause damage. Of course this would have to happen when it's stinking hot and humid.

[plucka99]

It is probably overcharged now. He was needed to recover refrigerant and weighted it to establish if there is right or wrong quantity of refrigerant in system. Only then he could charge by weight right amount of refrigerant.

No he didn't recover/weigh it, Just checked with his guage. So an overcharged system could stop cooling?

[rude]

Could be anything really it might not have anything to do with the work he previously completed. Id call him back out to have a look.

[nicolacozma]

The first thing that an technician have to do when discover that there is not enough refrigerant inside of the system, is to check, find out and repair the leaks.
Only to add some refrigerant is a non professional procedure. As result the technician will spend a lot of time - because have to come back- and of course the client is not soddisfied.

Regards,
Nicola

[nike123]

No he didn't recover/weigh it, Just checked with his guage. So an overcharged system could stop cooling?

Not completly stop, but could significantly influence performance.

If he connected gauge manifold and judged charge by monitoring only one value (suction pressure) then he cannot conclude about state of charge and correct it without other measurements (temperature measurements of outdoor air DB indoor coil air in WB temperature and suction pipe temperature) and consulting some charging table.

[sinewave]

Just had my first service done a week ago on my 4 year old ducted aircon.

[nike123]

So what?

[sinewave]

Yeah, maybe you're right!

[plucka99]

Tech just came out, says the problem is a broken/blocked filter in the outside unit, blocking the coolant. Apparently a known problem with this model. Of course he didn't have a spare with him so a few more days of sweltering

[plucka99]

Not completly stop, but could significantly influence performance.

If he connected gauge manifold and judged charge by monitoring only one value (suction pressure) then he cannot conclude about state of charge and correct it without other measurements (temperature measurements of outdoor air DB indoor coil air in WB temperature and suction pipe temperature) and consulting some charging table.

He has a dual gauge, for low and high side. Low side was far too low hence his reasoning of the blockage.

[nike123]

He has a dual gauge, for low and high side. Low side was far too low hence his reasoning of the blockage.

I see only facts.
1. Unit has looked to be working perfectly OK
2. Technician came to service maintenance unit with no symptoms of problem and said that unit is short of gas
3. After that he has charged some unknown quantity of refrigerant
5. After that unit started to loose performance and developed some symptoms of fault
6. Technician came again and now he say that it is blocked filter drier
7. Blocked filter (if that is the case) symptoms has been apparent after his previous actions but not at beginning of story

When he came first time did he firstly cleaned air filters and washed indoor unit coil and after that connected gauges on system, or it was other way around?

[plucka99]

I see only facts.
1. Unit has looked to be working perfectly OK
2. Technician came to service maintenance unit with no symptoms of problem and said that unit is short of gas
3. After that he has charged some unknown quantity of refrigerant
5. After that unit started to loose performance and developed some symptoms of fault
6. Technician came again and now he say that it is blocked filter drier
7. Blocked filter (if that is the case) symptoms has been apparent after his previous actions but not at beginning of story

When he came first time did he firstly cleaned air filters and washed indoor unit coil and after that connected gauges on system, or it was other way around?

He checked the gauges last. Changed Air Filters, flushed drain pipe, don't know if he washed coil- indoor unit is in the ceiling space so I didn't watch what he did up there.
Maybe this "filter" was on its last legs, and then with the added pressure of the top up gas caused it to breakdown.

[nike123]

Yeah, maybe you're right!

I have my Fujitsu window heat pump AC 13 years old, never touched with any sort of tools, only seasonal filter cleaning and washing of coils with mild dish washing soap solution.
It appears that it does not need any service.

[nike123]

He checked the gauges last. Changed Air Filters, flushed drain pipe, don't know if he washed coil- indoor unit is in the ceiling space so I didn't watch what he did up there.
Maybe this "filter" was on its last legs, and then with the added pressure of the top up gas caused it to breakdown.

It could be the case.

[munya72002]

they might have failed to completely shut the service valves after gas top up so they might be leaking off slowly thats why it took about a week to break down..ask them to thoroughly check for leaks coz it must be a very small leak..get bck at me anytime

[icemakerman]

Where are the flare nuts?

I think he said he added about 1KG. He replaced/fixed some valve where he suspected the leak came from also.

Could the system be damaged if run while out of gas? I imagine it had been running all afternoon before I noticed the problem. Also if I turn the system on again now to seems to work again, initially anyway, I suspect it would fail again but don't want to run it in case I cause damage. Of course this would have to happen when it's stinking hot and humid.

sounds like an overcharge ,,what brand of system,, what capacity in kw i would get them back to repair it refuse to pay any extra though as it sounds like a shonky tech to me lol