Air con - what's going on here?

[pikey]

I've got a professionally installed split unit in the bedroom that's been working through the night quite happily for the last 2 months.

Last night it decided to turn into an ice maker. Some of the ice the fan caught, wizzed around and spat into the room and some of it melted! Exciting as it was, I don't think it should do this!

It was quite humid last night and the compressor was on working (rather than just the fan) but the room was at 21 with the set temp at 19 so it's not as if the temperature sensor was broken and it was trying to freeze us.

It's under a full warranty but before I call them, what's likely to be the problem/cause?

Thanks

[jaybkay]

Had this once with a unit I installed, great fun with ice flying around. The "cold" in an air conditioning unit is from liquid refrigerant boiling off, hence it suggests to me either the refrigerant is too low (leak) or the expansion valve arrangement is faulty.

The unit I fitted had a faulty indoor unit which was reducing the pressure to much so the refrigerant was going too cold - as yours has been OK up till now there must be something else causing excessively low temperatures - get the installers back.

[eddie1980]

Best guess would be a leak of refrigerant. As suggested above get the installers, or someone with gas and gauges to check it.

[pikey]

Ta. Installers contacted

[John MacK]

Is the air filter clean?

Does it cool okay when running, if you can check the temp of the air coming out it should be about 7deg C cooler than the air going in. If it is about 7 deg then gas should be ok.

[pikey]

John MacK said:

Is the air filter clean?

Does it cool okay when running, if you can check the temp of the air coming out it should be about 7deg C cooler than the air going in. If it is about 7 deg then gas should be ok.

Thanks John. To answer your questions.. I haven't checked the air filter (unit is 6 weeks old). Should I?

The air coming out is cold. Not sure about being 7 degrees colder than outside air as I didn't ask it to, but if it helps the room it's in (loft extension) 'collects' heat and humidity and at the point it was icing last night I noted it was 21 inside, 17 outside (and the unit was set to cool to 19).

It's always set to 19 and normally (ie. when it doesn't do anything I would note is not right) I wouldn't check the temp so I presume is around there.

The thing that woke me was the noise of the fan picking up the ice, as normally it's completely silent. The cooling seemed ok really.

[SJobson]

It's not surprising the cooling seemed OK if it were set to 19 when the outside temp was 17 - it doesn't need to do much cooling

[John MacK]

Normally the filter shouldn't need cleaned for a few months, but if is in a dusty environment e.g. If building works were going on when it was running, dust from standing etc, it may need cleaned.

What make is it?

Is it just cooling a bedroom?
Is the door kept closed when the unit is running?

[pikey]

SJobson said:

It's not surprising the cooling seemed OK if it were set to 19 when the outside temp was 17 - it doesn't need to do much cooling

Not that simple as the room is always hotter than the outside. It's a modern loft bedroom (on top of a hill) with loads of mandatory eco-regulated insulation and direct sunlight on it from 5am to 8pm so any whiff of heat and the room stores it. This morning the temp on the roof was 38degrees!

I normally turn the a/c on a few hours before going to bed and the external compressor works hard to reduce the temp and humidity, then just silently ticks over on fan to maintain the set temp.

[pikey]

John MacK said:

Normally the filter shouldn't need cleaned for a few months, but if is in a dusty environment.
What make is it?
Is it just cooling a bedroom?
Is the door kept closed when the unit is running?

Room dust free and clean.
Made by Sinclair.
Yes, just cooling a bedroom.
Doors & windows all closed when running.

[spitfire-ian]

pikey said:

Not sure about being 7 degrees colder than outside air as I didn't ask it to

The temperature of the air coming out has no bearing on what the controls are set to. Setting a room to 19 degrees doesn't mean you'll get air coming out at 19 degrees, it just means it'll stop throwing cold air out when the room gets to 19

[John MacK]

pikey said:

Made by Sinclair

Never heard of them.

Google search makes me think possibly Eastern European copy of Chinese copy of previous generation Japanese unit.

If the installers are coming back then good luck hope they find a problem and fix it for you.



p.s. I presume that wasn't expensive?

[pikey]

John MacK said:

pikey said:

Made by Sinclair

Never heard of them.

Google search makes me think possibly Eastern European copy of Chinese copy of previous generation Japanese unit.

If the installers are coming back then good luck hope they find a problem and fix it for you.

p.s. I presume that wasn't expensive?

It's a Czech company who organises a Chinese assembly of Chinese and Japanese components, with offices in the UK (as well as worldwide), sold & installed through a UK distributor. Comes with a 3 year guarantee.

Just spoken to them & they're round soon.

As for expensive, I think it's expensive, but you may not. It's certainly very expensive compared to a B&Q unit (that leaked gas & couldn't be recharged), an ebay cheapo Toshiba unit that kept breaking but the supplier wouldn't send someone to fix it and a portable floorstander (which is sooo NOISY!).

The cost was £1,500 for two 12,000 btu units (different rooms, different floors) connected to a large outdoor unit (dual compressors). Took 3 people the best part of a day and I had to have scaffolding erected. Expensive? Yes. Less expensive than some other quotes? Yes.

Edited by pikey on Thursday 6th August 09:40

[pikey]

btw, all fixed. Fault was insufficient coolant for the run. For the unit with the fault there is 12m of pipe.

On installation the young/new guy said it needed extra coolant for the run, the older one with 20+ years air con engineer experience said what it came with from the factory was sufficient.

Turns out there is a chart that says it did need more!

[John MacK]

Cool.