Home AC question

[otis24]

My home central air unit is older. It's at least ten years old, because that's how long I have lived here. It's an off-brand. I've had a slow leak in the system and it needs the freon recharged at least once each summer. Repairman says it could be a small leak and would probably be hard to find. I'm thinking he may just be milking me each summer.

Is there a sealant that could be put in the system that would stop a smaller leak? I know that it can be done with autos, not sure about home units.
Thanks in advance!

 

[cowart]

The first step is to *find* the leak, if there is one. If you can access everything, get a clean paint brush, and paint all the tubing, connections, etc. with very soapy water. Watch for bubbles forming and note the location.

 

[diamond90]

There is a product called super seal that finds leaks I have a Heating and Cooling business (A & A Heating and Cooling) and we use that for our customers.

 

[zonker5]

If you just need to charge it once a year I'd live with it. Be a lot cheaper than replacing the system.

 

[Kodiakco]

If you just need to charge it once a year I'd live with it. Be a lot cheaper than replacing the system.

If and I say if a contractor follows proper EPA procedure, the leak must be found and repaired. It is also not good for the system. Air and moisture can get into the system. I am a refrigeration tech also.

Sent from my DROIDX using Tapatalk 2

 

[bricker]

If and I say if a contractor follows proper EPA procedure, the leak must be found and repaired. It is also not good for the system. Air and moisture can get into the system. I am a refrigeration tech also.

Sent from my DROIDX using Tapatalk 2

This. Too many shadetree techs trying to sell refrigerant by the pound. Can't sell it if they fix the leak.

 

[SOFMatchstaff]

First, check the service ports for a slow seep, soapy solution or leak finder, if that shows a visible indication, use a valve stem tool to VERY carefully seat the stem, and then seal the caps(there are caps, yes??) with thread tape, hand tight +... If thats not the area of leakage, start looking for a OIL spot indication anywhere there is a union, solder or otherwise. If freon is leaking, so is the oil, good indications of leaks. As slow as the loss is its most likely a low side leak.

I have found the service ports are a common area for rip off leaks to be introduced. Hope this helps

Old ThermoKing Mechanic...

 

[chief38]

The average life expectancy of a central air unit is about 15 years, so if yours is already 10+ I would not recommend putting in any major bucks at this point. A few hundred, yes, but much more than that I would just put toward a new unit with a high efficiency rating and a good warrantee.

 

[T.L.R.]

Our central air compressor unit, (Tempstar), is 23 years old, and still working well. Back about ten years ago the Freon all leaked out over Winter. A brass fitting had cracked and leaked the Freon out. Replaced the fitting, refilled the system, and has been good ever since.

cowart is right. You have to find the source of the leak first.

On a differentnote, I have 1996 Saturn we bought new with 337,340 miles on it and the A.C. has never been serviced, and is still "iceberg cold".


T.L.R.

 

[MK]

Usually a leak that is large enough to require a topping off once a
year is large enough to find with a decent leak detector.
As mentioned, all the service valve caps should be checked, but
there is a decent chance it has a leak somewhere. It's often in the
evaporator coil. The end plates where the elbows are fitted, rust,
and when the rust bad enough they start to warp and cause leaks.
But... it could almost be anywhere.. If the evap coil is leaking, a good
detector will pick it up.
I have both handheld "modern" type units, but I still often prefer the
old GE style detector that runs off 117v. It's the one I use when trying
to find small leaks. It also seems a bit more precise when hunting
than my solid state hand held thing..
They do now sell sealer that comes in a can.. I saw it at the supply
house the other day. But I've never used it, and generally would
consider that a band aid approach. I'm also leary of stuff that could
clog things I don't want clogged..

BTW.. if it has service ports with pump down valves, make sure
the large brass caps are not leaking. That is semi common. If they
are, just use blue "leak lock" on the threads and put them back on and
they won't leak.

 

[RightArm]

From all of these posts I would say a different A/C tech is definitely a move you should make in the future. Sounds like any of the previous posters would have fixed the problem rather than recharge it every year.

 

[amazingflapjack]

Some good sugestions. TLR is very fortunate to have a 23 year old system still working, but depending on the climate you are in, the cost of running a unit that old could easily buy a new unit. They will run a long time if maintained, but the inefficiency has greatly improved over the years. I replaced my old 6sere unit about 6-7 years ago with a 15 sere Trane unit and the savings, as well as the performance was absolutely dramatic. Nurse the oldie along while you look for a deal. I am very fond of my Trane with its variable speed air handler.

 

[CAJUNLAWYER]

Usually a leak that is large enough to require a topping off once a
year is large enough to find with a decent leak detector.
As mentioned, all the service valve caps should be checked, but
there is a decent chance it has a leak somewhere. It's often in the
evaporator coil. The end plates where the elbows are fitted, rust,
and when the rust bad enough they start to warp and cause leaks.
But... it could almost be anywhere.. If the evap coil is leaking, a good
detector will pick it up.
I have both handheld "modern" type units, but I still often prefer the
old GE style detector that runs off 117v. It's the one I use when trying
to find small leaks. It also seems a bit more precise when hunting
than my solid state hand held thing..
They do now sell sealer that comes in a can.. I saw it at the supply
house the other day. But I've never used it, and generally would
consider that a band aid approach. I'm also leary of stuff that could
clog things I don't want clogged..

BTW.. if it has service ports with pump down valves, make sure
the large brass caps are not leaking. That is semi common. If they
are, just use blue "leak lock" on the threads and put them back on and
they won't leak.

I put myself through college and law school in part by servicing and installing HVAC. Our leak detector was a torch with a rubber tube attached to the fitting at the base. light the torch and the flame was blue-pass the hose over a leak and it turned green. great way to find leaks. Of course back then, in a pinch we also used the tank of 22 to blow out a clogged pan drain once or twice Also know what a Pittsburg machine and a break is too!!

 

[Glock It]

Don't mean to hi-jack, my AC system leaked out at the cooling coil (corroded) in the attic. Its a Carrier brand 3 ton (?) unit, almost 10 yrs old - had fixed leak in copper tube outside under the fan already... Im in nasty hot/humid Houston... they want $2,000 to install a new cooling coil! Is that a "normal" cost or is it pure sodomy?

 

[LVSteve]

Don't mean to hi-jack, my AC system leaked out at the cooling coil (corroded) in the attic. Its a Carrier brand 3 ton (?) unit, almost 10 yrs old - had fixed leak in copper tube outside under the fan already... Im in nasty hot/humid Houston... they want $2,000 to install a new cooling coil! Is that a "normal" cost or is it pure sodomy?

I suspect that may be the going rate. They are effectively replacing half your A/C system.

 

[LVSteve]

My home central air unit is older. It's at least ten years old, because that's how long I have lived here. It's an off-brand.

Many of the "off brands" are built by the usual suspects and rebadged. Mine says "Day and Night" on the front, but after plugging some of the part number gobbledegook into a search engine I found it was a fairly standard Carrier unit.

Is it a split unit with lines in the walls? I have always wondered about those since I first moved from England. Few homes have A/C there so I took special interest in this novelty when i got here.

 

[Glock It]

I suspect that may be the going rate. They are effectively replacing half your A/C system.

Wow! Fudge!

 

[otis24]

I replaced the coil a year ago. The drip pan was metal and had desintegrated. New plastic drip pan and coil. Hopefully, if the leak was at the coil, that has been resolved. I guess i won't know until I see if I needed a recharge this summer.

 

[MK]

Don't mean to hi-jack, my AC system leaked out at the cooling coil (corroded) in the attic. Its a Carrier brand 3 ton (?) unit, almost 10 yrs old - had fixed leak in copper tube outside under the fan already... Im in nasty hot/humid Houston... they want $2,000 to install a new cooling coil! Is that a "normal" cost or is it pure sodomy?

Pretty much normal. I'm also in Houston, and have done A/C work since
the late 70's. There is a good bit of work involved in changing a coil.
Also you have to pull a city permit these days, which adds about $100
or so to the price. If that was included in the price, that's where $100
went.. And the price for coils and copper are pretty high right now.
The price of copper is so high, many companies are now going to all
aluminum coils.

 

[MK]

I put myself through college and law school in part by servicing and installing HVAC. Our leak detector was a torch with a rubber tube attached to the fitting at the base. light the torch and the flame was blue-pass the hose over a leak and it turned green. great way to find leaks. Of course back then, in a pinch we also used the tank of 22 to blow out a clogged pan drain once or twice Also know what a Pittsburg machine and a break is too!!

I've seen those, but never tried one.. I've been doing it since 1977..

Know what you mean about the drains.. We have the little CO2
cartridge things, but you only get one whoosh of air, and they are toast.
I just got a new doohickey for clearing drains a couple of days ago, and
haven't tried it yet. It uses no cartridges, but has a hand pump type of
deal. It will blow or suction drain lines. Hopefully it will pan out as
useful..
I often use a water hose to backflush drain lines. But you have to check
the attic for any openings first.. I have PVC caps for up pipes, etc..
The water hose gets out that Marvin Zindler rated slime better than
pretty much anything. I've seen unbelievable nastiness come out of
some drain lines.. Gooey slimy gunk in a variety of pleasing color
schemes. :/