LG Multisplit ongoing issue... slowly getting there I think!

[Brian_UK]

Hi Richard, good to hear that things are progressing somewhat.

Thinking out loud, as they say.....

The fact that the fans run is not indicative of a controls fault simply one of refrigerant flowing where you don't want it too.

Are you prepared to modify the system outside of the LG scope?

A. When a unit goes thermo-off can you interface with this control signal somehow? In other words, could you connect a relay which would switch over when the 'stat goes off.?

B. If yes, then see about fitting shut-off solenoid valves in the pipework so that the flow is stopped when at thermo-off.

[back2space]

Hi Richard, good to hear that things are progressing somewhat.

Thinking out loud, as they say.....

The fact that the fans run is not indicative of a controls fault simply one of refrigerant flowing where you don't want it too.

Are you prepared to modify the system outside of the LG scope?

A. When a unit goes thermo-off can you interface with this control signal somehow? In other words, could you connect a relay which would switch over when the 'stat goes off.?

B. If yes, then see about fitting shut-off solenoid valves in the pipework so that the flow is stopped when at thermo-off.

Good evening Brian

I trust to find you well?

Thank you for your response, I would be prepared to look at these options as everything else has been tried but would like to see if increasing the pipework length to the minimum that lg specify. Would this cause problems when the unit goes into defrost? Also think that modifying the control signal as my engineer would prob charge me a small fortune to do that... hes good at what he does mind.

The fan runs on the other units occasionally when they are at thermo off when the coil gets a build up of heat but no where near as much as the unit that is on the 2mtr pipe run... where when it reaches thermostat off there is still enough heat build up in the coil to keep the fan on constantly with an air off of 38C matching the unit that is calling for heat. This in turn raises the room temperature higher and higher until the other units are all at thermo off.

The other units at thermostat off the coils are at about 27C and the fan only comes on for about 10seconds every few minutes to clear that heat build up but this doesnt cause the room temp to rise even though the rooms are smaller. The fact this is only happening on one unit suggests that it is piping length issue but I need to understand how the short pipe work might cause a build up of heat in the coil enough to keep the fan running and cold air prevention off.

So do you think the short pipe run could be causing this heat build up in the coil when the eev is supposed to only be 10%? You mention its not a controls issue so all units should be behaving the same 2 out of the 3 are so the EEVs on them are open the same but then these units are on a longer run.

Increasing the pipe run might be enough to stop as much refrigerant getting to the coil in one go maybe?

Thank you once again.