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My mother's HVAC system suddenly quit working in our 90-degree heat outside on Thursday. As best I could tell, there was no air coming from the vents too. ((But hold on to the clincher below.)
Called a service guy who said the system was shot and needed replaced. The system is about 10-year old or so. Well, that is a lot of money for my mom (she is a retired widow whom I help of course) and is a lot for me right now. So hoping it could be repaired we called another company to look at it. They looked at it on Friday and could not get any parts over the weekend but thought it would be about $3600 to fix it by replacing the compressor and other things (they called today on Monday and said it would be $6300 now...sheesh).
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But here is the weird thing, on Friday the thermostat set point was on 70 degrees and the inside temperature was 89. Friday night everything started working and the temperature went down to 70. It stated this was all night and into the next morning and into the afternoon.
So on Saturday afternoon, out outside thermometer was at 93 degrees mid-afternoon and inside the house was right on 70 degrees. The day got hotter and the outside temperature was 99 and the inside was now 74 degrees (I had read somewhere that above 95 degrees the system would not work as efficiently).
Later on Saturday as the outside temperature returned to the low nineties and high eighties at night, the inside temp was at 70 again. It remained perfect until Sunday afternoon when it quit working again completely. The temperature rose inside to the high 80's again. We had turned the unit off in the afternoon.
At about 10pm we turned it back on and all started working again, inside temp returned to 70. It is now Monday afternoon and the system still has the inside temp at 70.
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So the second company calls me back a few minutes ago (Monday afternoon) and gives me the $6300 price and saying that a valve in the compressor is bad/weak and this means the compressor has to be replaced amongst other things.
After he gave me the info, I told him about the unit working for most of the weekend and how that fit into the analyst. He never gave me an description that made me understand what he was trying to say (I am an engineer btw)...basically he said that the unit was overheating and the valve would stick or something and wouldn't let it work. Then by turning it off, it would cool down. And with this, the system still needs $6300 worth of repairs.
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So finally, thanks for hanging in on this novel...It is really hot outside and these problems did not arise still the outside heat got into the 90's...even though on Saturday it ran successfully all day with the outside temp in the high 90's. I can't help by wonder if this is a factor on the "over heating". Spending that kind of money right now will be a disaster for us, but if required we will figure a way...but before I do that, I believe these repair people should be able to explain to me why it works so well for long periods then not (i.e. overheating seems logical) and with that how a system that seems to work so well most of the time will take $6300 to repair?
So hopefully someone here has the expertise to explain some of these things or point me in another direction that might work. I will give you my thanks now as I am very appreciated to anyone that shares their knowledge and expertise with me. Thanks!
Ordinarily, compressors either mechanically work or they don't. Electrically, they rely on capacitors which are prone to fail and cost is less than $50. you can buy a nice fluke meter that measures micro farads ( a capacitor measurement)for not much money to determine capacitor health. A compressor will usually overheat due to excessive amp draw (bad cap) or a low charge.
I get less than $300 for a dual run capacitor, 2k'ish for a compressor R&R and 3-4k'ish for a simple condenser swap out.
Check out acca.org for a qualified contractor in your area and ask for an honest assessment.
Sound like the OP has run into two different BAD techs. Not all that uncommon, and depending on what else the OP said to the tech, maybe they assumed that because of the situation it made more sense to "replace the whole mess".
That said, I completely agree with btuhack that things are NOT ADDING UP! If the compressor is "shot" it would NOT come back on and manage to keep any sort of place comfortable in 93 degree heat. Just NOT GOING TO HAPPEN! And it 100% true that things like the capacitors fail pretty much like a 'burned out light bulb' -- once the gut of a capacitor no longer hold a charge it cannot be "healed" by cooling it down...
What MIGHT explain the change from "dead" to "working pretty well for given high temps" is a one of the many 'safety & efficiency devices' that are increasingly part of newer AC units. And yes, 10 years qualifies as NEWER!
Just for reference one can get a ball park of the "material costs" of replacing the compressor and heat exchanger, though I would NOT recommend using a big box store -- Shop Central Air Conditioners at Lowes.com
Location: Stuck on the East Coast, hoping to head West
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Is this a heat pump?
It sounds like the inside or outside unit might be freezing up. You can check the outside unit and you should be easy to see ice (despite the heat) somewhere on the unit. I've also had the indoor air handler freeze up, but you have to take the cover off to see that.
I had an older heat pump and when there was more than a 20 degree difference between outdoor and indoor air, the unit would freeze up. I'd have to shut the unit down, wait for everything to thaw and then I could try to turn it on again. At the time, I couldn't afford repairs or to replace the unit for a couple of long summer months so I watched outside temps and set the indoor thermostat for no more than 20 degrees lower than the outside temp. This worked for me.
Assuming we're talking about heat pumps---mine generally last 10-13 years. I'd compare the cost of replacement to repair. Might be better off buying a new one.
No air coming out of the vents is a tip off for a possible problem - the inside coil may have restrictions and freezing up if the temperature of the air going across it isn't hot enough.
The problem needs to be duplicated and then someone needs to look at the air handler fan and the evap coil to check for problems there before doing much else. $6,300 for repairs? Yeah, right. You could fly a tech in from Texas cheaper.
No air coming out of the vents is a tip off for a possible problem - the inside coil may have restrictions and freezing up if the temperature of the air going across it isn't hot enough.
Yep, and the unit may have the wrong pressure which will cause one to freeze up. Even a restriction like a pleated filter can cause one to freeze up. I'd check the filter first and make sure it isn't dirty. Use only the cheapy fiberglas filters. If you need more filtration like pollen, spray it down lightly with Armorall.....yep, the automotive spray stuff. It remains tacky and pollen will stick to it. The filter will need to be changed at least once a month if you use the Armorall.
My first thought is freezing also. Could be as simple as being low on refrigerant. This is assuming that with no air coming out of the vents, the blower motor was actually running.
I would like to know what this system is - and where it is. Here in Florida - 10 years is about the useful life of a compressor. I wouldn't spend 10 cents to repair a 10 year old compressor - would just replace it. Robyn
Another problem with the 10 year old unit is that it's probably an R22 unit and you can't refill it if it's low on refrigerant, and you can't just fix it and fill it with the new legally required refrigerant. If it's leaked out, or just low, you will still probably have to replace both the inner and outer units anyhow due to that.
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