Now having a bit of trouble, after I installed awning in my backyard. I realized there is nowhere for technicians to carry down the outdoor unit for servicing in the future. Unless they go all the way to the backyard path. Is it possible to do a general cleaning and service without taking the unit down?

It's the internal cooling coil. Suggest you take a look, it's the fins behind the filter. Probably clogged. A professional can dismantle and wash it for you around 50 or so.
Gas is seldom the problem unless it's leaking.

If leaks then the technician can probably replace the part. Otherwise no point to refill, it'll just leak continuous
The technician can probably tell, they have a gauge to measure the normal range. But very rarely this is a problem. Just ask for normal service wash the internal cooling coil, and request they check the pressure too since it's free to check.

This post has been edited by itekderp: Dec 9 2016, 03:19 AM

Outdoor unit needs cleaning perhaps. Or even the indoor, since don't think the chemicals are as good as a proper wash. When you ask the technician just ask them to check the gas pressure. Not sure what normal range is for house ac but you can probably find that out easily.

Outdoor unit sometimes can get clogged, it doesn't have filter only the fins. If you have the time and a good pressure washer, can try to clear it yourself. But be careful. Don't bend the fins, always spray a distance away.
Not sure about pressure, but I think house air conditioner gas can slowly lose pressure or something. That's what the air cond guy tells me anyway. Even though technically it shouldn't unless there's a leak? Not very sure

Takes around 5-6 months here before it gets clogged up, Sarawak. Should be way faster in city I think.

Does leaks affect the same way as car ac system, as in spoiling the compressor through debris etc. We've been taught/scammed all this while by technicians who insist on "topping up gas", which sounds nonsense considering its a closed loop. But could recharging the gas be used to test for leaks as preventive measure? I know it works somehow like that for cars, the vacuum seal needed will indicate leaks.