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View Full Version : daikin unit pulling vaccuum on cooling


phil hempo
10-09-2009, 08:36 PM
hello guys ,have recently replaced a compressor on twin fan daikin condensor pressure tested , vacced out and recharged correct amount . condensor works on heating but when in cooling mode had gauges on suction side and it pulled down to a vaccuum and went off on low pressure fault , could it be a faulty diverter valve . if any of you fellas have encountered the same problem i would appreciate some help .
marc5180
10-09-2009, 08:40 PM
Are both your service valves open....especially the liquid?

If they are then the unit is pumping itself down due to some sort of restriction.

Is the gas charge correct?
What pressures did you have on your discharge/liquid
Andy AC
10-09-2009, 09:53 PM
Did you install it?, or have you inherited someone elses mess? Could be blockage in strainer of indoor unit - piece of armaflex from not sealing ends of pipe during install. Could be worth a look.

Andy
Brian_UK
10-09-2009, 10:28 PM
Reversing valve stuck.
nike123
11-09-2009, 05:34 PM
Reversing valve stuck.


It is hardly that stuck 4 way valve could make suction pressure go in vacuum. It will make high suction pressure and low discharge if it is stuck at half way, or if it will stuck in heat mode and instead of cooling it will work in heating mode.
acnerd
11-09-2009, 05:47 PM
It is hardly that stuck 4 way valve could make suction pressure go in vacuum. It will make high suction pressure and low discharge if it is stuck at half way, or if it will stuck in heat mode and instead of cooling it will work in heating mode.

I agree .... and in addition another symptom : you may land up with a very high pressure suddenly. When the HP cuts the compressor out, the pressure will stay very high on the gauges!

It does make me wonder if your EEV is not opening up in cooling mode on the outdoor unit. Can you hear it clicking when the power is turned on?

The only other symptoms I've ever witnessed on Daikin units pumping themselves down is because of water in the pipes!!
nick uk
11-09-2009, 08:16 PM
does it have a suction strainer before the compressor had one of these crumple and cause vacuum
wandowski
14-09-2009, 07:40 PM
i would reclaim the refrigerant,then blow ofn in the liquid valve and see if i get it back from the suction side,then i know i got a circuit and can eliminate restriction and start looking at valves