LG Inverter AC problems

[dan_4818]

Hey guys,

I have a LG Reverse Cycle Inverter airconditioner (r410) thats having some problems that i cant identify.

When in heating mode the pressure at the suction service valve is reading around the 5000kpa mark but when in cooling mode i only get a reading of around 200kpa and the liquid and suction line ices up. Could this be some sort of blockage in the system.

Where would you recommend i start looking for the problem?

Cheers, Daniel

[The Viking]

Is the indoor fan running?
Filters clean?
Indoor coil clean?



.

[dan_4818]

No nothing is runnings. No indoor or outdoor. Unit is brand new first time it has been switched on.

[dan_4818]

Nevermind that last one. Was thinking of a different unit. But yes, the outdoor and indoor fan are running. Unit has been installed for a week so no dirty coil or filters

[install monkey]

check the gas charge-weigh it out,also check the service valves are fully open too

[dan_4818]

Service valves are fully open. i havent weighed out gas charge but it is a brand new unit and the pipe run is within the maximum length before adding extra charge. If its short of gas it wouldnt be reaching 5000kpa when heating would it?

Thats why im thinking blockage somewhere. In cooling it is pumping down causing the lower pressure but in heating the pressure rises as it is reversed if that makes sense>?

[martinw58]

was ofn used whed brazing pipes if not pos blocked filter.was all the ofn removed after pressure test have you checked the refrigerant with pt chart

[martinw58]

have you checked the expansion devise is opening if not this will give you high hp in heating and low pressure in cooling

[AGSelec]

Electronic expansion Valve is where I would be looking.

[dan_4818]

How wOuld I test the expansion valve to see if it was faulty?

[Yuri B.]

If there are yet other units check whether the pipes are not mixed up.

[frank]

I would confirm the charge to rule it out as a possible cause. A frosting liquid line (after TEV/capillary on A/C) is usually a sign of SOG.

[install monkey]

2 bar suction in cooling and 50 bar in heating mode,kinked pipe? or not vacced or debris in pipework

[monkey spanners]

2 bar suction in cooling and 50 bar in heating mode,kinky boots?

http://www.youtube.com/watch?v=bxKBnS8GKSM

[AGSelec]

How wOuld I test the expansion valve to see if it was faulty?

Well I had this problem once on a Mitsubishi I got hold of the service manual which had the ohm values of the EEV

And I don't have a manual for this LG ac, so not sure what the set up is.

[spimps]

www.mylg.co.uk might help

[nike123]

I would say that Install Monkey is on right track!

I would pump down unit and inspect pipes and indoor unit with OFN for pressure drop.

[martinw58]

hope this helps

[martinw58]

did you find the problem

[savoc]

hp pressure to high, blocked, kinked pipe or not vac correctly. Sometimes the gauge line depressor dose not depress the schrader valve and you only vac out your gauge line. dont laugh see it done. check pipe work, blow nitro threw lines, vac and weigh in correct charge, if fails still. call out warranty agent.