First post, please be nice, prob with heat mode

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Hello Gents

My first post hope you guys can help me.

DOnt want to call out a service tech as we feel we get fobbed off all the time.

We have 2 indoor convertible units connected to a multi split system one in in the living room & the other in our extension at the back. The system works perfect in cooling, maintaining room temp to within 1 degrees C, so comfortable room conditions are always possible in this mode.

However we are having a problem with the maintaining of room temps. THe system has no problem outputting heat but far too much of it.

If a temp of 22c is selected on the controller, the unit will sometimes continue until room temp reaches 3 or 4 degrees above this limit, meaning the temperature is very high and uncomfortable, and when the unit needs to kick back in it doesnt come back on quick enough meaning large differences in room temperature. We have noticed that the unit doesnt measure the room temp once the thermostat has shut off as the fan stops completly and doesnt come on again until well below set point as I guess it is measuring the temperature inside the unit which is going to be warmer as the thermister is behind a nice warm filter! I know that the coil sensor will stop the fan operating if its below 28c but in the manual still states the fan shud operate for 10seconds every 3mins to measure ambient... it doesnt do this and lg say it should do this despite their manual saying otherwise!

We have measure the temp at the intake of the unit where the sensor is and we have noticed because these are mounted below our window sill about half a foot from the floor that the temperature down there is usually 1 or 2 degrees below what our digital thermometer says on our mantel piece. SO this is probably why it is not shutting off at about 22/23 as it hasnt reached that desired temp at the intake sensor.

We are not sure what to do as presently we feel we are not getting benefits from the unit and will revert back to our cheap portable electric heaters as these maintain the temp better.

We want to know what our options are with regards to this, the equipment is LG (some sighs i hear from doing a search on LG) LG say there isnt a fault with the units and we feel we are getting fobbed off our installer also doesnt seem to think there is a fault.

We have had to look into matters our self and had advise of heating engineers

We have noticed that if the sensor is poking out the intake grille so it is sensing the room air the unit comes back on if the temp drops below the set point by about 1.0c so we know that if its inside the unit in its correct place because the fan doesnt "cycle" every 3 minutes this is why room temp drops too much.

We also have figured out that because the temp at floor level is going to be cooler than at the mantel piece this is probably why the unit is staying on for a lot longer with the large temp increases.

With this being an inverter as well we find it still cycles on and off everytime it reaches thermostat off, it doesnt seem to wind down enough and it uses more electricity than it did on cooling mode when the outdoor temp is about 12c so its not having to work that hard either! The whole reason we spent so much on a system was to save money!!! Sometimes the actual time the system is giving out heat can be as little as 4minutes on and then 15minutes off. Is this bad for an inverter as we were told they dont shut off only wind down. Again on cooling mode works perfectly no probs whatsoever, with longer cycles on but still cycles off at set point. The units were purposely oversized so that they can heat and cool the entire ground floor of our house which they do very well! They were oversized by about 1.5kw we were told at install to allow for this? Perhaps this explains the cycling issue also in heat mode?

What can we do now to avoid these large temp increases? Is it possible to install one of those room thermostats like you control your central heating with as these are very precise i think? Our hotel room on holiday had air con where you could only control the room temp and had the same as in the pic attached. Room temp was always perfect.

Sorry for the long war and piece but judging from other peoples posts it seems that you guys prefer to have more information than not enough.

Equipment are LG 3.5kw Convertible units.

Kindest regards
Julia