My central air unit's line is frosting over and the technician determined it was 3# low on freon. Suction pressure is 40#. He has suggested it would be wiser to replace the entire system (inside and out including gas furnace, 14 SEER, 34,000BTU for $6124 ) with a newer, more efficient unit based on 410A refrigerant. It seems to me that I would be better served attempting to have the unit repaired rather than jump immediately to an entirely new system.

I would like some advice on the wisest move for me to make at this time. My current system still cools, so I would like to believe there is some life left in it if I add some freon and find the source of the leak.

Any suggestions on a plan?

The right answer depends on several things. First of all how well do you know your service man and how well do you trust him? Next how old is your equipment? Next how long of a history do you have about this equipment, I mean have you just moved into the house or have you owned it since it was new? This will tell you how many times freon has been added to this unit.

Now not knowing the answers I will just give you some general answers. First if you are thinking about a new system get at least four estimates, making sure they are for the same size equipment and the same S. E. E. R. rating. A 16 seer will save you more energy than a 13 seer but will cost mort to buy and install, it will also have more gadgets that can need repairing. Therefore I would find out what a ten year parts and labor warranty would cost and if you did take the warranty who would be allowed to do the warranty work on the equipment. I would consider how long I was going to live in this house and try to figure how long the payback would be for the unit with the energy you would save from the new unit.

Now about repairing the old system, freon has gone up in the past few years but it still is not real expensive. So if you had to add three pounds of freon every couple of years and the labor is not outrageous that would not cost much. Also a good tech will spend a little time trying to find the leak and if he finds it and repairs it you might not need any thing but a little service for several years.

If you have more questions let me know.

Additional information about my system: It is 9-10 years old. I am not the original owner, but have run it three seasons without any problems. It appears to have had a repair previously due to the presence of an in-line drier. The tech speculated that it had previous compressor work, but that was before my time of ownership.

I would get another estimate on it, sort of sounds like a saleman not a service tech.

Have him top the unit off with the correct amount of refrigerant and see how it performs. Trying to recover 6,000.00 with energy savings from the new unit will take forever.

There is more to this than dollars. I think the technician is leagally required to find and fix a leak before recharging it. If one or both coils are turning to Swiss cheese, a new one maybe a good idea. Now that it is working, it should make it through the season. See how it does in the spring. Turn it on the first warm day while you still have some time to do something.

We have some experienced HVAC people here. Maybe one of them will check in.

First off don't call that service person back, the leak should be repaired before adding the refrigerant to your system. If he just added refrigerant and did not look for a leak, he did not do his job, three pounds is big enough to find with a decent leak detector.
If you decide to replace your equipment, get three bids from different contractors.
Good luck , Mike

((I think the technician is leagally required to find and fix a leak before recharging it)).

I suggest a trip to the EPA web site. The law does not state that the equiptment has to be repaired before charging! Many people are confused as to exactly what the EPA states so I always suggest they read it for themselves. Now as far as the leak goes I doupt the three pound loss. More than likely they told you this so you would buy a new piece of equiptment. I would never buy anything off any body who cannot fix the old one unless the compressor is bad or someone ran over the unit with a truck.. Indoor coils can be replaced for much less that 6,000.00. More like 500.00 to 750.00.

As was already suggested I would have another company look at the unit and while they are there they can give you another estimate.

First of all, thanks to all of you who responded. You saved me a lot of money. Here's how it turned out...

I called a different technician to investigate the system. He arrived in less than 1 hour, then I told him the symptoms as described above. He immediately noticed the drier on the large copper line running from the house to the condenser unit. He said the most likely place for a leak was there. He used a bubble solution and a mirror and found the body of the drier unit had a pin-hole leak. He removed that drier and the drier on the smaller copper tubing running from the house to the unit.

He put a new drier on the smaller copper line and soldered a new piece of tubing into the larger line replacing the old drier that was leaking. He checked to be sure the system would hold a vacuum. Then he had to add back an additional 5# of freon to fill the system. Two hours and $375 later, I'm back up and running. Sure beats $6000 for a new system, even if it only lasts me another year. :D