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loddy · May 4, 2008, 09:44 AM

I have a R410 mini split. Flare fitting leaked so I pulled all the gas out and fixed the leak ,
Put it in a vacuum and weighed in the charge. Unit came on and cooled but liquid line was very cold. Suction pressure was about 120 and 37 degrees. Well I went away for awhile and came back later. Both fans were running
But compresser was not. Unit is 1 yr old. My question is should the lquid line be that cold and did I damage the compresser? This unit does not have a high side port.

aldematt57 · May 4, 2008, 09:51 AM

Even without a service access port on the high side, you could have checked it's temperature and thus determined the pressure on the high side using a PT chart.
What you are describing is a compressor valve failure and a compressor shutting down on thermal overload.

loddy · May 5, 2008, 07:21 PM

Suction line was very cold so really didn't need to take temp. if valves were bad why did I have good suction line presssure when compresser was running.

aldematt57 · May 6, 2008, 08:01 PM

Sorry. For some reason I thought you were dealing with R-22. My bad.

Can you jumper out some safety switches and see if the compressor continues to run?
It's possible that a low or high pressure control could be taking the compressor out.
What are your amp draws when the compressor is running?

hvacservicetech_07 · May 6, 2008, 09:15 PM

Well, Is your TXV inside the outdoor unit? If so, that would make your liquid line cold. I know a lot of the ductless split systems do that. Have you put gauges back on the system since it has went out? Is it possible that you may have lost refrigerant?

hvac1000 · May 6, 2008, 09:58 PM

((put it in a vacuum and weighed in the charge))

Did you just let the unit compressor put it in a vacuum or did you use a vacuum pump and pull it down to the proper microns? If you just used the units compressor instead of a real good vacuum pump you probably have noncondensibles in the system causing a floating restriction which would allow the frost on the line to come and go as the restriction moved around in the system.

gottee · May 11, 2008, 09:06 PM

Ductless with only a single access port have the expansion valve on the inside of the outdoor unit. This is why both lines are insulated and it is not a liquid line, technically it would be referred to as the condensate line. Normally the Manu tells you what temp difference to look for between both lines. Inside the condensing unit is where you can find the high side access port if you need it.

P.S. With R-410 units, do yourself a favor and DON'T jumper the high pressure switch

mrblondie · Jun 29, 2010, 11:10 AM

Help got my r410 split installed and the guy didn't vacuum line, only access on the big pipe I'm guessing its low side.valves were opened the ac works and so does heat but I know its not right please help what do I do service companies don't want to come for less than 800 do can u but a pump and recover the gas then vacuum line please help I saw a pump on eBay 9k268 or something like that what is needed

mrblondie · Jun 29, 2010, 11:10 AM

Help got my r410 split installed and the guy didn't vacuum line, only access on the big pipe I'm guessing its low side.valves were opened the ac works and so does heat but I know its not right please help what do I do service companies don't want to come for less than 800 do can u but a pump and recover the gas then vacuum line please help I saw a pump on eBay 9k268 or something like that what is needed

sirjusingh · Sep 19, 2011, 05:33 PM

What gas pressure to use when gas r410 split unit 12000btu

shaddoe · Jul 31, 2013, 11:45 AM

Quietside minisplit with two air handlers with multiport outside unit ran fine for 2-3 weeks then indicated low pressure this is 410 system charge was correct at installation suspected leak reclaimed Freon pressure checked no leaks what could give low suction reading??