find freon leak

[lrning]

I have a MILLER central a/c for more than 10 year.

In July, the technicain replace the condenser (not the compressor).

the condenser is in the outside unit, next to the compressor

(Am I correct) because the condenser is rusted

The job cost is $600

this month (september), the house is really hot 81 degree F. So we call the technician back, he cannot find any leak, but he has to add Freon in.

And now the house is cool ok again.  So far so good.

I know that it is a lot of work to find a small leak, and technicians are on the clock to make the most money. I would do the same.

So what can I do to find the leak by myself.

any special tool to smell Freon R22.

it is leaking somewhere, because he had to add Freon

is there a post/ a link somewhere?

[certified tech group 51]

there are tools to find leaks............some are easy to use   IF the leak is large enough to find, you will need at the minimum, a leak detector...there are various brands to purchase............ Distributors like .Johnstone.......or  Armstrong,   parts places..........Some times you need a little help as in adding more pressure to the system to help the refrigerant leak, so the detector will find it....Now you need a charging manifold set-up , a tank of dry nitrogen with regulator.... pump up the pressure to 150 P.S.I........ If the refrigerant has leaked out you will need to add a charge of refrigerant to the system with the nitrogen to help find the leak ( do you have ways to get R-22??)  Another way is to add a filter/dryer with a dye to help find a leak , but those tools will add up to a few $$$...torch, 15% silver solder, R-22, charging scale, plus all of the support equipment.............Every step of the way you will need to follow the system from the compressor to the inside coils , checking all of the tubing in between.......

[lrning]

so to be exact June 25th fully charge

Sep 15 need to add freon to bring the temperature below

80 deg F total about 80 days

is this a small leak or large leak?

it is summer time, so the unit run everyday

it is a Miller 5KW central ac

[ACtechGUY]

Most leaks are easy to find. YOu have a relativly bad leak that should not be too hard to find. No expensive tools required.

#1. Mix up a dishwashing soap solution that makes bubbles easily( Children's soap bubbles are perfect) . Put this into a squirt bottle of some kind.

#2 The leak is likely at the evaporator coil, check there first.

#3 lOOK FOR OIL ON THE PIPING. There will always be oil at the site of a leak (An oily spot will be shiny and well, oily)

#4 At the evap. coil , spay down all exposed bends and all the little piping you see. If you see two small pipes touching, look there , copper pipes have a way of rubbing thru each other. **** if leak is where the ubends go thru the steel plate or in the section of coil that has the aluminum fins , you are toast. Time to buy a new coil.

If you find a leak in one of the small tubes you can see , call pro. this is not a DIY job. You don't have the skill or equipment to do it right.

#5 check the service ports at the condensing unit. make sure the caps covering the ports have o-rings in them . spay some soap in the shrader valves . If they are leaking you will see bubbles and that may be a problem. Check that the service valves have caps installed and are tight and not leaking. With your leak you will see large bubbles develope quickly.

*It is rare for leaks to be in the interconnecting piping.

*It is rare for leaks to be in condensing units.

[Bobice]

[user=32822]certified tech group 51[/user] wrote:

there are tools to find leaks............some are easy to use   IF the leak is large enough to find, you will need at the minimum, a leak detector...there are various brands to purchase............ Distributors like .Johnstone.......or  Armstrong,   parts places..........Some times you need a little help as in adding more pressure to the system to help the refrigerant leak, so the detector will find it....Now you need a charging manifold set-up , a tank of dry nitrogen with regulator.... pump up the pressure to 150 P.S.I........ If the refrigerant has leaked out you will need to add a charge of refrigerant to the system with the nitrogen to help find the leak ( do you have ways to get R-22??)  Another way is to add a filter/dryer with a dye to help find a leak , but those tools will add up to a few $$$...torch, 15% silver solder, R-22, charging scale, plus all of the support equipment.............Every step of the way you will need to follow the system from the compressor to the inside coils , checking all of the tubing in between.......

Ahhh "Grasshopper" you forgot to mention must be EPA certified.