suction in vaccum high side in vaccum

[still learning]

had a dakin rzq125 to day with these symptoms,it was not running , when we arrived , and found a low pressure fault. leak found on suction flare , unit reclaimed , found to be short of gas , or so i thought , re charged with correct amount , unit run with both low and high in vaccum, asumed blockage somewhere , reclaimed again, but did not get full amount back. reclaim rig pulls down to vaccum but if you wait gauges show gas trickling back form unit. any idea's where to look for the blockage and why.

[The Viking]

When you say "High and Low", is that the connections on the shut off valves the pipework is connected to on the outdoor unit?
If so then both are on the low-pressure side of the system and you are probably looking at a blocked/faulty EEV or a blocked strainer.
There is also a true HP port further inside the unit, IIRC it is almost hidden behind the compressor.

[install monkey]

daikin rzq inverters are prone to eev's sticking in the closed position,be careful trying to locate the blockage as there is still refrigerant in the system that you are struggling to remove-try energising the 4 way valve and listening for gas movement

[still learning]

we reclaimed from the suction side where the shut off is and the port near the reversing valve and this is where we have taken running presures from. there is another port just above the suction shut off.
would exessive moisture cause my problems ?

[still learning]

i tried to switch the unit from heating to cooling , but the indoor controller did not display the heating mode , as i did want to see the the 4 way valve work , i was indoors and my mate outside .
the unit shuts down on lp.
i am aware of the trapped gas , which the reclaim rig will not pull out , thanks for the warning .
if removing the shraders from the shut off ports no gas comes out ( pipework side ), but it does from the two internal ports .

[The Viking]

would exessive moisture cause my problems ?

Well, yes...
Not to mention the fact that the oil is hygroscopic and also becomes ACIDIC as soon as it comes in to contact with any moisture.

Why? You think there is moisture in it?

[install monkey]

8551 found a pic of the pipework layout for the outdoor unit

[still learning]

suction flare freezing and drawing in moisture , as unit freezes back on suction line .
normaly we would renew the flare, if it was found to be leaking ( bubble test), and would of seen moisture in the pipe , as have seen this before , tommorow weather permiting i will look down the suction flare and may see moisture .
i know about the hygoscopic oil, and hold little hope for this unit

[still learning]

thanks for your help guys .

[VRVIII]

What is the full model number? RZQ125???
There are around 8 different models B7/B8/B9/C7/C8/D7/.... most have different internal piping and the newer units (Cx & Dx series) have a reclaim/vac mode, this is enabled via the outdoor PCB push buttons similar to VRV.
If the unit has a solenoid purge valve at the top of the receiver (most Bx series) this can be energised by a standard solenoid magnet to give clear passage or both internal gauge connections must be used.

[VRVIII]

B7 Piping 8552

[still learning]

problem found to be a faulty check valve, so i was was told , we were dispatched elsewhere, luckily we had some parts from a scrap unit.
thanks for your help .

[EastsideMatt]

I have a similar problem, the unit model i am working on is a Daikin RP125L7W1. i found the unit short of gas, reclaimed, blew pipes out with nitro because i thought it might have been a blockage then pressure tested and held for 12+hours. after all this left on vac over night and added refrigerant and same problem occured with the suction and discharge both pulling a vac?? would this be the same problem?? and how would i locate the 'Check Valve'?? :mad:

[Gary]

we reclaimed from the suction side where the shut off is and the port near the reversing valve and this is where we have taken running presures from. there is another port just above the suction shut off.
would exessive moisture cause my problems ?

The liquid line is always high side. The true suction line between the compressor and the reversing valve (#12 in the pic you posted) is always low side. All other ports are high or low depending upon mode.