Air Conditioning - Coolant leak test.

My 7 year old cental air unit is leaking coolant. The first repairman replaced coolant which was gone within a month. Second repariman (different company) said to check for the leak a gas is injected into the system and a period of five weeks needs to go by before a leak can be detected. The cost for this check is $500 dollars then the cost of repair. Can you give me an idea if this sounds to high? Thanks

They are talking about injecting a dye. I don't know about the cost, however it's not the only method of leak testing. Find someone who will come and use an electronic leak detector to look for the leak. A leak that looses most of the charge in a month shouldn't be too hard to find. First place to look is the indoor coil.

I agree with John. If you lost your refrigerant in a month they should be able to find it pretty easy. Did the guy with the dye even attempt any other methods?

No, he didn't use any other method to find the leak. How does the electronic detection work?

http://www.bacharach-inc.com/PDF/Brochures/8003%20H10%20Series.pdf

Here is an example. They will just "sniff" around and a alarm will sound in the presence of refrigerant.

I'd say you are getting ripped by the guy. It shouldn't cost anywhere near 500 bucks to find & fix a leak. I use an electronic sniffer that will find even a tiny leak. The leak you have should be obvious and would be quickly & easily found with an electronic sniffer like a TIF ZX-1.

The AC guys I have had come to the house do all the troubleshooting for the initial service charge, which in my case is $69. The 'sniffer' will find the leak in a few minutes usually. In my case it took 9 months for it to leak out and freeze up the evaporator coil. Even then it all had not leaked out (just about 2# of it) The sniffer sounded off in about 1 minute of being put into the evaporator coil chamber.

Even injecting the dye I'd think the cost wouldn't be over the cost of two service trips + maybe 20$.

Run, don't walk away from this guy.

Thanks for all the good knowledge. My gut told me this price was to high. I had electrical service increased into the house. The company also works on air conditioning units. Tomorrow, they're getting a call. :cool:

:) I'm having the company who did the electric come out Wednesday. They quoted a price of $79 to diagnose with only a 3 day turn around if they have to use the gas dye. Thanks! :)

In your 1st post you said it was gone in a month. That's why we thought it was a easy leak to find. 9 month leak could just be a bad schrader core.

The dye should cost no more than $30 and like the others have said, a bad leak shows up very quickly. If the other charge had been lost in one month, we would add the dye, start the unit and check immediately. If the leak is big, sometimes the dye makes a big mess and actually has to be cleaned off to watch the pinpoint source. I think you are on the right track now.

Ken