Lg multi fault eev not opening

[back2space]

Ok so a bit of a repeated post as my other post from 2014 was closed down so here it is again.

Im having same issues still, outdoor board was replaced and makes no difference. 4 indoor high wall units connected to one outdoor condenser (Fm25ah ue1). The issue is that randomly say 2/4 indoor units will not call for cooling despite there being a demand. The outdoor unit operation icon doesn't show up on the controller and the compressor doesn't run. A power reset at the mains will rectify this, then it could change to ¼ units that won't operate or 4/4 units will run for a short time then similar issue occur. There is no way to get it to call for cooling even turning on and off at the wired remote and resetting the controller does nothing.

My upstairs units have been running all night this morning I've gone down to turn the lounge unit on, it turns on etc, fan blows set point is 21c room temp is 23.5c on the controller and it will just get cooling it seems. There are no error messages displayed on both outdoor or indoor sides. Compressor is already running serving the remaining bedroom unit that is still on... compressor even ramps up but eev doesn't open... Thing is if I power reset it at the breaker it will all will work for a bit then it might be a different unit that doesn't operate properly the next time I come to operate them and it's been turned off a bit. Very confusing to say the least. I've recently downgraded all indoor sub pcb's to 7000btu from a mix of 12 and 9000btu units. This was done as units were too big for the rooms. I've even changed the indoor pcb on one affected unit to ensure that it wasn't a dodgy indoor pcb wasn't causing issues. There are no fault codes displayed so I am unsure as to what the issue could be. We are now having to reset the power at the breaker to get the indoor units cooling. Indoor units call for cooling (we know this as compressor ramps up) but eev doesnt open to supply refrigerant to indoor. We know the EEVs are working as a power reset at the breaker means it will work for a bit. The EEVs should then be opening to let cooling back through but they dont. If we physically turn ¾ indoor units off and one unit that was calling for cooling but not getting any cooling the outdoor unit continues to run but no refrigerant goes to that unit so the EEV is remaining closed. After a few minutes compressor shuts off as the refrigerant isnt going anywhere then after 3 mins rest time the outdoor unit comes back on and cooling commences on that unit and refrigerant flows.

Sometimes you can turn one indoor off and that will then let the eev open on another unit that was calling for cooling sometimes followed by a loud hiss from the valve opening and the pressure equalising across the indoor unit. If all 4 indoor units were turned on but not cooling we do a power reset for a couple of mins, some of the indoors then dont turn back on whereas they used to do so following a power cut etc and 2 of the wired remotes actually fully reset back to factory defaults such as the time etc whereas they used to remember it for an hour or so... anyway all 4 indoor units will then work ok in cooling until one will reach thermostat off, if that unit should then call for cooling and the outdoor unit is already running the eev will not open until one of the other indoors reaches thermo off or is possibly turned off completly but compressor ramps up knowing it has extra load. It really is very difficult to describe properly.

My engineer says impossible to pin down the issue and it could still be an indoor board or boards that are causing the issues. He said the indoor unit tells the outdoor when to run but we know its getting that signal as the compressor ramps up but sometimes the "outdoor unit" symbol on the controller doesnt illuminate and sometimes it does but until that eev opens no cooling commences. Run the system as a 1/1 split with just 1 indoor on and it runs fine, ive tried every single unit individually and even disconnected every other internal unit from the electrical side of things so that the outdoor thinks only 1 is physically connected. I assume the outdoor unit board controls the EEV position based on the information it receives from the indoor boards and the fact these issues happen across all 4 indoor units in no particular order means that all 4 indoor boards cant be faulty and outdoor board has been replaced. There are also no comms errors or any other codes coming up.

This issue has been more apparent since the sub boards to change the capacity were changed to lower capacities. I believe this because the units are now matched to the cooling load of the room so cycle for longer. Checked with the original high capacity sub boards (3.5kw) and the same behaviour occurs but because it doesn't take very long for one room to reach temperature the unit cycles off meaning the unit that is waiting for the eev to open can then begin cooling.

Hopefully someone will be able to help. I would say I've had the outdoor unit since 2007 and had no end of trouble with the indoors and outdoors but had new indoors fitted when I moved to this house in 2012.

Thank you

[install monkey]

when reset the power, the lev's should drive closed- should hear them chatter when they get to the end- have you tried replacing the lev heads? maybe replace 1 to see if this cures it, never touched lg kit as its never been good . another bodge is if theyre screwed onto the lev body then maybe loosed the nut to a few turns could be pins sticking , lev head cycling open but pin sticking in the closed position

[back2space]

when reset the power, the lev's should drive closed- should hear them chatter when they get to the end- have you tried replacing the lev heads? maybe replace 1 to see if this cures it, never touched lg kit as its never been good . another bodge is if theyre screwed onto the lev body then maybe loosed the nut to a few turns could be pins sticking , lev head cycling open but pin sticking in the closed position

Already been checked as they work independently when only one unit is running but not when more than 1 unit is running and they reach thermo off at different points and then cut back in etc. as a 1-1 unit they control properly.