Finding leaks- electronic,nitrogen, ultrasonic....

[tcape]

When I get a call about an AC system that is not working and find it low on charge, I usually do the following. Wondering what the most time saving method is for leak checking/locating is?

If I don't know the unit history, I will try to find out from the customer how often they had the system recharged in the past. If they can't remember or say it was a few years ago, I usually suggest a visual inspection, and electronic detector test(I use HP10). I will usually charge the system before I start that, after having explained the next step(nitrogen).

If that fails to yield results, then I tell the customer to call me when they notice things not working up to par and if it winds up being low again, they know I am going to do a nitrogen test.


I usually pump the system up to the manufacturers test pressures if I can find the info or about 200psi

If I can pump the system down I can isolate the condensing unit from the rest which can make it easier to get everything running again if the leak is in the coil or the lineset or joints where each connect.



I've been able to find several leaks by hearing it hiss using nitrogen. What would you think the safe limit is on pressurizing the system to make leaks easier to locate?

If I find any suspects I usually try to soap bubble test the area, because I want to show the customer the actual leak. Is Big Blue the best for bubble testing?


Are there any other sure fire ways or more convenient testing equipment I could use to find leaks?

This can be a pain in refrigeration too...

Thanks

[bmathews]

I look for oil first. If it is new construction and the system is flat empty and no oil at the braze joints. Probably a nail in the line. If the house has been there for several years with no problems, you can usually eliminate the nail in the freon line thing unless they put up a shelf or something in the vicinity of the lines. Then I start the search, if the leak finder can't find it. I'll nitrogen test it. If its a Carrier CK series or a non tin plated coil. You've probably found your problem.

[beenthere]

Get your post count up to 15, and apply for pro membership.

We don't discuss how to find leaks, or other technical issues in the open residential forums.

[cc2cuz]

I can relate to the nails through the refrigerant piping deal. A couple years ago I was on a project installing a/c systems for 68 condos. The stucco guys used extra long staples just to install their chicken wire to the ext walls and hit about half of all the systems we installed. Bad thing was that we didn't find out until after all the stucco was done. This kinda stuff happens all the time. thats why after I finish a rough-in I like to pressurize the lines with nitrogen instead of leaving them in a vacuum, that way if someone hits my line, booom, they will definitely hear it.