Check Central Air For Leaks

acci

How do you check for a freon leak in a central air conditioner? What steps does a service technician take to check for a leak. I would like to do some checking myself and if need be hire a service technician. I would like to gather some information to also check the competency of the technician. Thank you.

HVAC Doc

Probably not something you could do yourself unless you want to shell out some money for either a good leak detector, a nitrogen rig to pressurize the system to test pressure specs, or invest in a UV dye set up in which the dye is injected into the system and ran for a day or two then checked with a UV lamp. Something a person can do is feel for oily spots at brazed connections which often signifies a leak.

CynicX

How old is the system and what area are your from?...easiest way to use dye is to wait for the charge to run low before checking....I seen systems with leaks that take a couple years to run down if thats how long it takes the dye is a really hard to see, and if the charge takes more then 2 days to run down you'll never hear nitrogen...if this is an old system your leak is most likely going to be either in the indoor or outdoor coil...changing an indoor coil isnt that tough but outdoor is a real PITA....as hvac doc mentioned you can visual look for oily spots (minerial oil in a R-22 system used for lubericating the compressor).....HTH

acci

System is about 11 years old. I had the system recharged last year and it worked for the season. When I tried it again this year, the air was not cold. I am in Illinois. Can you give me an idea of what it would cost to do a leak test by a qualified HVAC technician? Thanks.

CynicX

really depends on area, here in Maryland you'd be looking around 50-90 trip/diag, 75 for dye insertion plus the refrigerant it needs then 50ish for the search later on....and they will find it in a coil indoor or out and you'll end up replacing the thing anyway....you might want to baby it (i know doesnt sound professional) but if it last the entire season its gonna be kinda tough to find the dye....some of the newer more sophiciticated (sp?) sniffers are really acturate unfortunitely they are very expensive so I dont have one, and my sales abilities exceed the need for one....but at any rate the average life to a system in maryland is 15 years give or take, I'll assume its pretty much the same in your area. With that being said now would be the perfect opportunity to look into a new system and get all your "ducks in a row"....and you can baby the system you have now, maybe even take out a service policy with a good local company that includes bi-annual services....this way they're check the charge every year and most techs, at least i do, if we find the system low on charge we'll add some since we're doing subcooling anyway w/o charge (unless it takes a massive amount)....alot of times if you have a service policy with a company you'll also get a discount on a new system.....