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Post by bazza44 on Apr 6, 2023 11:40:31 GMT 10
After ideas here. We have a 2008 Dometic B3200 aircon that is not used very often, but the last time was in January with about 38* - 40* outside. With aircon on it was about the same temp inside as outside.
I have removed the top cover and blown out the condenser etc, was ok anyway. Fan speed works as normal just not cooling enough. When I had a house aircon bloke here last month for the house air con I asked him to check the van, he said he did not know much about them but he checked up top and showed me a pipe that was frosting and said that to him this meant it was working as it should.
I checked the thermostat by turning the button with the power off and could hear a click which I think means it is ok. Now where to from here, depending on results from colonoscopy on the 14th we will either keep the van or sell it. Will need aircon working to sell it and want it working if we keep vanning.
Electronic parts cost around $300 ea plus maybe $200 to $600 for labour. Or a new one for $2000 plus install. I do not think I can do it myself anymore, too awkward up on the roof of van. I am leaning towards a new one but did not want to spend that much.
Barry
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Post by Old Techo on Apr 6, 2023 11:54:48 GMT 10
Baz,
It is not a reverse cycle to complicate things with a gas reversal valve.
Should be a simple check. When the compressor motor is running there should be a lot more noise and vibration compared to fan only.
The compressor should turn on/off according to thermostat temperature setting.
If you set it to max cold and the ambient is not too cold then the compressor should be able to be heard/felt. Switching then to fan only should be noticeably quieter.
If you can confirm compressor noise but still no cooling it must be a lack of gas.
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Post by bazza44 on Apr 6, 2023 13:22:30 GMT 10
OT the compressor clunks and my first thoughts were low gas but the house air con bloke said the frosting of the pipe showed all ok to him. But as I said he does not work on these.
Barry
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Post by Old Techo on Apr 6, 2023 15:50:11 GMT 10
When you say it 'clunks' do you mean clunks just when it starts or tries to start? Can you then actually hear it running continuously?
I had noted your frosting comment but ignored it. I think that low gas pressure can cause frosting closer than normal to the expansion valve. So it depends which pipe and where the air-con guy checked.
The compressor compresses the gas and leaves the out pipe hot, enters the condenser that cools the gas and liquifies it, then it passes through a restriction called the expansion valve and then very cold it enters the evaporator. The fan blows air through the evaporator fins just like a car radiator and out comes cold air.
Baz, this is how I see it. An air-con that worked OK once now does not and it has not been damaged in an accident. If the compressor runs and its output pipe is hot or too hot to touch then it is doing work. If there is frost on any pipe anywhere then it is working to some degree as an air-con. If the fan is blowing air through the evaporator but it is just not cold enough then there is performance issue.
It is not a digital situation go or no-go. It is an analogue situation where it works but not well enough. The only analogue factor I can imagine is... not enough gas.
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Post by dieseltojo on Apr 6, 2023 17:24:09 GMT 10
OT your reply is so interesting so glad to have you and JR on the forum.. we are most fortunate fo a small forum...
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Post by bazza44 on Apr 6, 2023 17:42:40 GMT 10
Thanks OT, I can remember feeling a hot pipe up there last time I had the cover off. The frosted pipe was behind the evaporator. I have just about convinced myself just to get a new one. If this one has a gas leak there is an unknown time to find the leak and then can it be fixed. These air cons are not made to be re-gassed so an adapter would have to be fitted to the end of the pipe. All more cost at high labour rates.
I am now thinking of an easy way for me to fit a new one as I want to spend enough time to fix anything found when the old one is removed.
Thanks again for your input OT.
Barry
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Post by jr on Apr 6, 2023 18:41:59 GMT 10
Hi Barry, There should be a couple of Schrader valves (tyre valve) that a air con man can fit his special gauges and see if the gas pressure is ok. If not they can pressurize the system to find the leak. If you get a really good air con man they maybe able to repair the leak but if not yes a new air con.
JR
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Post by Old Techo on Apr 6, 2023 21:06:35 GMT 10
JR,
At least 30 years ago they had pipe piercing fittings intended to give one gas line access when none existed.
I did a bit of searching and found they still exist and here is an example piercing valve
I wouldn't fancy using one as a long-term fix as I'd worry about eventual leaking.
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Post by bazza44 on Apr 7, 2023 10:29:05 GMT 10
Thanks JR still thinking, if I take the van to a repair place and say let the tech investigate for about an hour and maybe waste $150 ? If he can find the leak in that time then say it can be fixed that would be good. Probably fixed for about $500
But the air con is 15 years old, and the life of these if you can believe what you read is about 7 years, so is it worth fixing and hoping that is a long term fix or is it a waste of time and money that could be put towards a replacement.
The replacement has to fit where this one is and size matters as the outside unit is close to solar panels and the hole in roof is 355 x 355. New ones need 360 x 360, so opening will have to be modified.
Still thinking.
Barry
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Post by GerryP on Apr 7, 2023 11:15:18 GMT 10
JR,
At least 30 years ago they had pipe piercing fittings intended to give one gas line access when none existed.
I did a bit of searching and found they still exist and here is an example piercing valve
I wouldn't fancy using one as a long-term fix as I'd worry about eventual leaking. OT, they're commonly known as "Bullet valves", not sure why but as a retired fridgie from way back, I've used heaps and not once had a leakage issue, even after many years. JR, Any good fridgie should be able to diagnose the problem well within an hour and give you an idea as to what is wrong and whether it can be fixed. From what I've read it's either short on refrigerant, the compressor is stalling (crook start capacitor?) or the compressor has lost efficiency (unlikely but possible). If it's a leak then that can be difficult to find, but these days they inject a dye into the system and use a UV light to look for traces to find where the leak is. I'd say it would be worth getting it looked at before deciding which way to go. Good luck mate...
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Post by jr on Apr 7, 2023 13:45:34 GMT 10
OT, never seen a piercing valve/bullet valve but had heard of them. Barry my van is 16years old now and my air con failed about four years ago due to a fatigue crack in the condenser. It is a Hero Q split system and the condenser is not a replaceable item. With much fiddling I managed to silver solder the crack by sweating a copper plate around the tube and naturally the crack was on the facing inside of the tube so was not easy to solder, mirrors and all that stuff. As a caravan air con does not do much work like a domestic one the compressor and all the control stuff should last more than seven years but the real killer is vibration an fatigue. My brother has just fitted one of the new Dometic air cons and it is much quieter. His old one was still working but very noisy. JR
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Post by loub on Apr 7, 2023 16:44:38 GMT 10
Yes I just replaced my working a/c.From being inside with a jet engine to relative quiet the new one is worth ever penny.Its an ibis 4 and very happy with it.My original one was 15 years old as well.
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Post by Old Techo on Apr 7, 2023 17:06:23 GMT 10
Our van air-con last month was 19 years old. Bought the van brand new but factory date was late 2003.
It is a roof-mount reverse cycle and never had any functional problems and still works like new.
Yes, it is noisy
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Post by bazza44 on Apr 8, 2023 8:16:23 GMT 10
Thanks everyone, I will get it checked first before deciding which way to go.
Barry
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Post by Mick Themungrel on Apr 16, 2023 0:59:45 GMT 10
Barry, if you are going to replace your A/C have a good look at Haughton brand. We fitted an HB3500 to our van in early 2018, as we live in our van full time, it has had a good workout since. www.razorrv.com.au/air-conditioners
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