Daikin split System cant get suction pressure out of a vaccum Help plz

[stephen 22]

I've got a Daikin RYP100 L7V1 split wall mounted R407C system. The system has the correct weight of refrigerant. The suction pressure wont come out of a vacuum. I have tested the 4 way valve which seems ok. I changed the head of the expansion valve with another unit which was working ok and the suction pressure still pulls into a vacuum. The 4 way valve was changed recently is it possible that the heat from the valve change could have damaged the expansion valve body? Or could it be a blocked strainer? If anyone could help me please that would be great as I am stuck.

[charlie patt]

have you done a flow check poss blockage ot eev shutdown/ on startup does it level up? service valve part shut/ is it on a long piperun? when shut of does pressures level up? how long does it run for remember those daikins have a pump down button

[thebigcheese]

pull the strainer just after the expansion valve, have seen a few of these blocking up

[Tesla]

Hi Stephen
I recently worked on a Daikin Split (horrible things). Replaced the compressor and had low suction pressure for R22 about 40psi. Phoned tech support and they advised to chang the PCB, compressor contactor and two thirmistors. The problem was still there, considering my knowedge and experience is limited I handed the job to another more experienced tech. He removed and recharged unit by weight as I did and the same poblem is there. Now it is a six week wait for a capillary set as #3 capillary is blocked. Would have been cheaper to replace the unit. Check for frosting on capillaries and ensure indoor coil is clean.

[thebigcheese]

just seen your from ni, is this a site in belfast?

[VRVIII]

Stepen 22,
How long did you let the unit operate? On start up these units do a type of pump down which last around 90secs.

If the mains power is switched off then back on you should be able to feel the EV motor driving, you can also hear a ticking sound from the EV as the PCB verifies the valve is fully closed when power is switched on.
Have you tested the unit in both heating and cooling mode? Does the internal piping show signs of overheating with welding tourch? The interal piping has 4 check valves, refrigerant flow is allowed to pass through 2 of the check valves in cooling and passes through the other 2 when operating in heating. If these check valves have been over heated the plastic iternals can melt causing a blockage.

I would suggest you reclaim the gas charge, split the internal piping and purge OFN through the pipes to identify the location of the blockage. You can also purchase a magnet to manually open the EV for testing.

[AbsoluteWDJ]

I've got a Daikin RYP100 L7V1 split wall mounted R407C system. The system has the correct weight of refrigerant. The suction pressure wont come out of a vacuum. I have tested the 4 way valve which seems ok. I changed the head of the expansion valve with another unit which was working ok and the suction pressure still pulls into a vacuum. The 4 way valve was changed recently is it possible that the heat from the valve change could have damaged the expansion valve body? Or could it be a blocked strainer? If anyone could help me please that would be great as I am stuck.

Check your service shut off valves before anything else.