mini split leak

[jjrbus]

3 year old Diakin is low on refrigerant. Can't seem to find tech that will look for leak. So I am looking for leak. Tried soap and water to no avail. Ordered some high tech fluorescent HVAC liquid leak detector. Still can't find a leak.

Returned refrigerant to condensor and charged lines and evaporator to 260 psi, no sign of a leak. Looking for leak detector, but am hampered by having refrigerant in condensor and none in lines/evaporator. Considering it only took a few seconds to drop the pressure to zero I have to assume there is little R410a in the system. So do not want to release it and run system as it may damage something.

Too much time reading on the net and seems that a hypersonic leak detector is what I need, does not detect refrigerants but the sound of the gas escaping, hopefully will work for me. Need to find job to pay for tools, I am not looking for work an easy high paying job is all I need.

https://www.amazon.com/gp/product/B00G1Y4DDE/?tag=atomicindus08-20

 

[bluedog225]

I guess you could have a leak somewhere odd. Not at the couplings. Hope you find it.

 

[fitter30]

Rectorseal ac leak sealer used this on mine. 2 ton with 3 wall units. Not cheap i used the 1.5 oz been working im surprised tried finding the leak with 600 lbs with trace gas. Single evap they make a .5 oz.
No more than 10% of compressor oil capacity. Moves with the oil.

 

[whateg01]

I put dye in every automotive ac system I work on but I've yet to successfully locate a leak because of it. I use a tif leak detector. The nice thing about a halogen detector is that you don't have to be able to see the leak to find it. The downside is that if there is air movement, it can appear to be a leak "everywhere".

 

[jjrbus]

Sealers make me nervous, absolute last resort. I do my own cars also and used oil with dye. Never found a leak because of the dye. Did find one leak with the cheap halogen detector, but too many false readings.

I am hoping this ultrasonic works out. If it does work well, I may place an ad for leak detection and recoup some of my $$$$$ it also detect air and gases.

 

[pcmeiners]

Before buying best you look at leak tester reviews, there are higher rated/cheaper than the one you posted. such as......

https://www.amazon.com/dp/B00DAOI5EQ/?tag=atomicindus08-20

As to testing did you check for leaks in every square inch of the coils?

 

[jjrbus]

Reviews are a matter of peoples opinions, interesting and I always take them into consideration. When I surf the net on ultrasonic leak detection a lot of the pro's are using the Accutrac and one other one??, but rarely see them with the Inficon.

I spent a couple hours today making leaks so I could learn what the detector is finding!

 

[motterpaul]

I have seen more people recommending Rectoseal along with recharging the lines. When you say "soap & water" be sure to use either DAWN Extra with distilled water - or the commercial bubbles they make for HVAC testing.

I am going the nitrogen route for testing under higher pressure - but if your lines are already loaded with R410a you could consider trying heating mode ALONG WITH BUBBLES. The heating mode in a split heat pump uses PSI as high as 450 psi (or so). Cooling does not go much above 120 psi.

I am a little curious why people don't mention heat mode more often - except that if you have a bad leak you could lose a lot of coolant at 450 psi (I guess). It is better to lose nitrogen than 410a - but it is also a hassle to pump a unit down and reweigh.

 

[American Locomotive]

OP can also close the discharge valve, and put the machine into "pump down mode". Most of the service manuals explain how to do this. It puts all the refrigerant back into the condensing unit, so you can safely open up the line set once it finishes pumping down and you close the suction valve off.

 

[danski0224]

The copper itself can be porous.

I've been sent pictures of bubbles forming on the copper line.

It has to be tested at 500 psi (or whatever the manufacturer recommends). Last couple I've been involved with were 500 psi for 24 hours.

Really need digital gauges, and your tools/hoses need to be in good condition. Or use a "stub gauge" or a "wireless probe".

HVAC manifold + hoses can be a leak fest for such testing.

 

[jjrbus]

Thanks for the responses, greatly appreciated. I am afraid to run the unit now as I have no idea how much refrigerant is in it? When I recovered the refrigerant, it only took about 20 seconds to drop to zero. I tried soap and water with no luck so bought the Calgon flourescent leak detector. I am testing with nitrogen, that only pressurizes the lineset and evaporator. I have no idea how much pressure is in the condensor?

I thought the Daikin would throw a code for low refrigerant, looking at the manual there is not a refrigerant specific code.

 

[danski0224]

Reclaim all of the refrigerant.

Pressurize the system to the manufacturer recommended test pressure.

Look for the leak(s).

Look for oil, that's a leak.