R410A leak detector

somewhereinusa · August 09, 2016, 03:22:43 PM

My mini splits work great but, I seem to have a really slow leak in one. Anyone have a suggestion for a R410A leak detector that won't cost an arm and a leg?

Thanks,
Dick

luvrbus · August 09, 2016, 03:44:42 PM

Use Nu-Calgon- Cal Blue bubbles, a sniffer is good for locating the general area,I have one I paid big bucks for and always end up using a $15.00 bottle of Nu-Calgon to pin point the leak

Sean · August 10, 2016, 07:09:32 AM

We just had a pro come out to try to find a very slow leak in our mini-split. He had two separate professional refrigerant sniffers as well as a pro-grade soap bubble solution and he still could not find it, even after we recharged the system and then ran it to full pressure. All we could do was tighten the four connections a bit more.

The advice he (and another HVAC company) had was to add a dye charge if it happens again. This is a small can of R410a with a UV-detectable dye added. The dye leaves a residue over time; after the system leaks back down, you go over everything with a black light to see where there has been dye deposition.

This is exactly what we intend to do if the system leaks down again.

My mini-split has two gate valves integrated into the piping at the compressor end; the compressor ships pre-charged. The valves operate with an Allen key and have threaded brass caps over them. On the theory that there might be slight leakage around the valve seals, I gooped the caps up with gas service pipe dope and reinstalled them. I also doped the threaded cap over the lone (low side) service port on the system after he was done.

HTH,

-Sean
now busless in Alabama

luvrbus · August 10, 2016, 07:19:11 AM

Some times it takes 24 hrs for bubbles to show on a slow leak has always been my experience with bubbles.A 1000 dollar sniffer will pickup a good fart before a slow Freon leak

. A smoke machine is the best way but they are expensive and a real pain to use

Dave5Cs · August 10, 2016, 07:36:07 AM

That's Cheaper than the wife!....

She will bust you quicker than one of those things....LOL

muldoonman · August 10, 2016, 01:26:03 PM

Have a cruiseair ( one of three) that leaks down, soap bubbles, sniffer, or dye hasn't shown leak. It's the front and the shortest run with tubing and easily to get to. Think the Gremlins are at work. Good luck.

robertglines1 · August 10, 2016, 05:27:45 PM

I used teflon paste on flares when installing. Recharge kit online E-bay under 60$ and comes with fitting and gauge. Watch tightening too much will crack flare. Been there on that one. For general info only. Good luck !

somewhereinusa · August 11, 2016, 05:32:58 AM

Quote from: robertglines1 on August 10, 2016, 05:27:45 PM
I used teflon paste on flares when installing. Recharge kit online E-bay under 60$ and comes with fitting and gauge. Watch tightening too much will crack flare. Been there on that one. For general info only. Good luck !

Bob, from your other posts, I did use teflon paste on flares. I bought gauges, scale and 25lb bottle because it was cheaper than one service call. I may get one of the recharge kits just to carry along if I don't find the leak.

Thanks,
Dick