LG VRF system No Heating mode

[grovecoooling]

Hi

I wondered if anybody could please help !!

I have recently taken over a maintenance of a Vrf 2 x pipe system consisting of LG
8 x ARNU15GCEA4 Floor standing units linked to
1 x ARUN120LTE4 Condenser
1 x wall controller

All units work well in cooling mode.
As soon as you change to heating the Heating icon displays for about 20 secs then the controller goes blank, there is no summer/winter switch fitted in the condenser.
The same happens if you change the mode from the centralised controller.
Auto mode say 30c set point, controller stays on auto but no heat from units

LG suggested i put the controller on the 1st unit and see what happens from there but i ran out of time, there is a trend system linking a couple of the other systems but this one appears to not be linked although trend are coming in to check.

Has anyone got any ideas of anything else i can do to check on the system ?

Thanks

[Shibhrac]

How many outdoor units are combine together?

[grovecoooling]

How many outdoor units are combine together?

Hi

Thanks for the message.

Only one outdoor unit unit installed not this system.

[Tayters]

Never dabbled with the VRF's but the splits would do something similar because the outside air probe was reading too high.

[nike123]

Check if all of the indoor units have closed switch of the filter section (must). Also check if all indoor units are on same operation mode (cooling, heating , dehumidification).

Also, if outdoor temperature is above 18°C it probably should not go in to heating mode!

[frank]

Is the outdoor unit located Outdoors or Indoors (i.e. in a factory/warehouse area)?