new comp,low suction !

Hi, help plz. If installed a new comp for a 12000 btu split, it was working well for days, then it stop cooling, the liquid line is cold, and only a little suction on the low side. Can the 4 way valve be the problem ? Thanks in advance

Sorry to be so obvious, but it does have all the hallmarks of 'short of gas'.

Trevor

I'd agree, it seems short of refrigerant if the liquid line is cold.
To test the reversing valve, take the pipe temperatures of the discharge in, discharge out, shouldn't be more than 2C difference. Likewise the suction in and suction out should be more than 2C difference.

Could be over condensing. Does it have a fan speed controller?

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Originally Posted by TRASH101

Could be over condensing. Does it have a fan speed controller?

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Split systems have the TX inside the outdoor unit, so the liquid line he's refering to as cold is after the flow control device. Normally that's not cold (as in under 10C cold), unless it's expanding too early, ie. low in refrigerant.
A split system short on refrigerant will normally have a cold "liquid" line. The easiest way to spot a split short of refrigerant is a frosted up "liquid" line.
On a normally charged split system system, the "liquid" line will be warmer than the suction line.

edit: like in a regular commercial system, anything low on refrigerant will ice up the entry of the evap and not cool effectively. In a split they will have a low temp or frost on the "liquid" line.

newly installed compressor means,the former compressor electrically burned or mechanically damaged where some foreign materials blocked a certain points of the system in general.

if the system was been flushed out,leak free and well vacuumed,we may say the aboved mentioned refrigerant shortage is the cause and additional charging is recommended.add some and observe.

if problem ,no cooling ,which is the specific problem of all the system exists,try to flushed out the system again and install new drier if it was not been changed lately and follow the basics steps of a leak free and cleaned system,b4 energizing the system.

thanx

Thanks to all your replys, hope to solve the prob!