Leak Repair Kits

[Makeit go Right]

Had an engineer go to deal with a slow/small leak on a 10kW system (30m run). He pulled out the R410a and pressurised with nitrogen but no joy. He could not find the leak despite a good look. His plan is to insert some leak-repair thingy with the refrigerant, which will run around with the refrigerant and find+plug the small leak.

That might be the case, but I am a bit worried about adding anything like this to the refrigerant.

What do the experienced engineers say about this stuff?

(Oh, also it is a 6yr old Daikin, and they have been having some issues with coils rubbing and causing leaks in hard-to-get-to places. Makes me wonder if this is another one of them crap-manufactured coils.)

[passandscore]

What nitrogen test pressure did you apply to the system? With 410a you can normally reach 500psi safely. When dealing with a small leak you need to increase the test pressure to the highest rating allowable as indicated on the equipment. Once you have a high enough pressure you should have no problem finding the leak, especially on smaller system like yours.

http://www.achrnews.com/articles/get...th-r-410a-poes

As for using as additive I would only consider it if the manufactures approve it otherwise it may cause more problems. Also, using a leak sealant it NOT a permanent fix. The leak will reappear over time guaranteed!

If your tech cannot find the leak try another tech. If you have a leak there is no reason it cannot be located.

[Tayters]

If it's the double fan type check with Daikin if the serial numbers fall in the affected range first off.
My old firm had one of these where the unit wouldn't leak under ofn (24hr test) but took a few months to show problems with the refrigerant in.
I found the leak on the coil, just took a bit of dismantling to get the leak detector in the right spot. Daikin sent a new coil (yeah, probably no good either!) and somehow a compressor turned up as well.

Cheers,
Andy.

[chemi-cool]

If you really want to find the leak and not just pump it with nitrogen then use helium instead, you will be surprised from the amount of leake.

Helium has very small molecules, much smaller then all refrigerants and nitrogen, widely used in locating leake in vacuum insulated vessels.
Also add Big blue leak detecting liquid to your arsenal, great stuff.

And dont add any "snake oil" leak repairing magic stuff, you might as well take a gun and shoot th unit....

Finding small and irretating leaks is part of your job, we all have these problems. its how we deal with them that makes the diference between fridgies.....

[al]

I have come across fridges with this additive in it, blocks capillaries and has led to premature compressor failure. Nitrogen is pretty poor for small leaks, as said above strip the outdoor, check all passes on the condenser and do the same with the indoor, if you're going to add anything, stick in leak detecting dye?

alec

[monkey spanners]

Try Trace-A-Gas from climate center, needs a special detector but the guy i spoke to at the trade counter found a leak that had been there for four years using it. Previously they had used dye, ofn, and even leak seal without good results.

http://www.agas.com/product/ProductI...ion.php?id=100

[passandscore]

I would recommend contacting the manufacturer before adding any dyes to the system. Not all dyes are created equal. You may compromise the system further. If you choose to use a dye be clean and careful. If you are sloppy you will transfer dye say from your hands to whatever you touch and it will be picked up with the UV light. This will cause frustration.

"It is important for a contractor to use an OEM-approved dye that is compatible with the system’s lubricant. Be wary of dyes containing cosolvents because they can adversely affect the lubrication qualities of the system’s oil, which can lead to premature compressor failure."

This quote and more is available via the link provided.
http://www.achrnews.com/articles/115...leak-detection

[Rob White]

.

I would ask if the stuff came installed inside the thing from new?
We all know the answer will be no, so in my opinion don't put
anything inside a fridge other than refrigerant and oil.

There is an OFN product that has helium at 10% mixed and it will
find leaks that are harder to find with OFN alone and there is a similar
product that has a small % mix of Hydrogen mixed inside and that is
effective also.

Regards

Rob

.

[still learning]

is it a dakin as tayters says , i have another coil on order .
what i do notice with these units is the tiny drip of oil under the base of the unit, generaly a first alert .
any twin fan i see now made by dakin gets a inspection on a maintanance visit.
i would pressurise the system with a gauge on the internals of the outdoor unit , be wary of lp switches and lock off the service ports and pressurise the pipework and indoor coil.
with another gauge to see if my leak was outdoor unit or indoor and pipe work .
the gauges used do not have a sight glass .
and bubble test gauge connections , to check my kit is leak free ( shut off valves leak well mine did ).
always down to time spent to get results , were luck here in jersey its all half an hour travel time away .
good luck .