AC Keeps running with power off

We have a Frederich SM18J30 18000 BTU through the wall AC on the first floor of our small Cape. It has been a work horse for 20 years without any big problems. Yesterday morning I turned the power off (was running all night) and the compressor wouldn't shut off. So now the compressor just stays on and the thermostat has no effect and I have to pull the plug to turn it off. I did some googling and it seems like it is probably a broken relay which makes sense. I am leaning towards replacing it because of its age but it still works well. Not sure if I can find someone to repair it. Finding parts might be a problem. I think most AC repair places around here deal with central air only. Should I break down and get a new one ($1600 is what I am seeing for a similar 18000 btu that fits this opening) or should I try and find someone to repair it? Thanks in advance.

Reply to
szeik
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A quick search shows most 18,000 BTU window air conditioners are in the $600 range- not the $1600 you mentioned.

For $600, I'd pop for a new one as it will likrly cost you a good couple of hundred buck to get that 20 year old one repaired. Also, new ones are much more efficient and use a lot less electricity

Reply to
Wade Gattett

It's through the wall. Those are the expensive ones. I also need to find one to fit the existing opening (27 3/8" by 17 15/16") Frederich makes several units that have these dimensions. So anything I would save on a smaller unit would be offset by the cost of changing the size of the opening.

Reply to
szeik

Some important factors:

1 - How much is it used, how much does the electric cost to run it? Like others have said, a new one will likely use substantially less energy, maybe even 50% less. 2 - Do you have the skills to replace a relay or control board yourself? What does the part cost? Are parts available? 3 - Any other issues with it, eg a higher or lower output one would be better, it's noisy, etc?

If the electric bills aren't too bad, a new one really costs $1600 and you can do the repair yourself, probably better to fix it.

Reply to
trader_4
[snip]

Is it your own home or a rental?

If yours, then it's probably worth doing some work and replacing that entire sleeve assembly.

Best option: You can get "mini splits" which are far, far, more efficient and quieter. $1,600 should come close to covering a brand new assembly.

Note that while most require a professional HVAC installation, there are some that come with "pre-charged" refrigeration lines.

Reply to
danny burstein

In the late 1950's, my father installed a Sears-Roebuck regular window a/c through a wall cutout he made in a finished attic bedroom. It worked fine for years.

Maybe designs are different these days-- or the manufacturers have hired sharp-edged marketing suits who have managed to convince folks that they need an expensive specialty device rather than a plain vanilla one...

Reply to
Wade Gattett

We own our home.

Those splits are nice. We have one for our finished basement. It would be a lot of work. Sheetrock, trim, vinyl siding outside, painting - probably the entire kitchen and hall which could use a paint job.

Not sure how much longer we will be here. Need something to get us through another 4 years maybe. Investing in these homes at some point is a losing proposition. Builders buy these for the land value and put up 2 story modern homes. Hard to get back what you put into these older capes.

Would love to just repair the one we have. Wish I was more handy but it is beyond my abilities to try and fix it myself.

Reply to
szeik

Problem there I would think is don't they pull air in from the sides and blow it out the back? It would need enough clearance on the sides for air.

Reply to
trader_4

Except a "window air conditioner" is NOT a "through the wall air conditioner" SOME will work in that application, depending on how thick the wall is - ithers will not (due to the location of the ventilaion openings on the unit which are restricted when installed "in-wall"

Reply to
Clare Snyder

I think you're in very good shape on this one because you know with 98% certainty which part is the problem, the relay, like you said.

Well, 90% I guess it might be the thermostat, but I gather your googling made pretty clear it was the relay. Relays can freeze closed becuase the current going through the contacts can make them stick to each other.

Open it up and look inside. There might well be only one relay, and the problem one will certainly be the biggest one if there is more than one***, with the biggest wires connected (2 of which will go to the compressor) or biggest leads on the circuit board, and two of the leads will lead to wires that go to the compressor.

It might unplug, and yoou might be able to get the part through Frederich, but if it unplugs there will probably be numbers on it to get the part from the manufacturer or part distributor. Using just the numbers even if no brand is stamped on it.

With the relay out and an ohmmeter, you can see if the contracts are closed and if you can get the cover off the relay, you can see with your eyesif the contacts are stuck.

Even if you can't get the exact part, you can get one that is electrically identical and if it doesn't just push in, you can solder the right number of wires to the circuit board and solder the other ends to the connectors on the relay. The wires can be 8 to 12 inches and the relay can sit someplace safe, so that if it has a metal case it won't short anything. You could cover that in electric tape.

I did something like this with my furnace for years. The transformer built into the control box burned out the first summer I lived here. Went to an AC supplier and he wanted about 200 dollars for the control box, and I knew it was just the trnasformer. I asked, Isn't there something cheaper and he offered me a transformer. 50% bigger than the original so I put it 12 inches away and mounted it with a screw and nut to the furnace case. I'm thinking there might not be a good place in an AC like you have so just stuff it anyplace where it won't short anything out.

If you can't solder, you can learn in a few mintues or you can find someone who can.

**My girlfriend, a girl no less, did this when her oven or fridge broke. The appliance repair man said he couldn't get the part. She got the part number off the little part and bought it online for $10 and put it in herself.
Reply to
micky

If it is the relay, it is possible that tapping on the relay with a screwdriver handle might un-stick it. It it begins working again, buy a replacement relay, and replace it the next time it sticks.

Reply to
Bob F

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