House AC suddenly not working!

[oldfella1962]

I know what you're thinking - "don't sweat it dude!" Anyway yesterday evening the house was feeling a tad warm despite the inside wall thermostat being set at 70 in the "cooling" mode. But by bedtime the house was naturally cooling a bit so I put the heat on for 70. This morning (before I would need the AC of course) I checked/did some basic things on my outside Rheem AC unit, like checking for any broken or torn pipes, wiring, etc. I cleaned the one coil area that had some dust & debris. I changed the filter in my hallway ceiling near the thermostat that is supposed to be changed on a regular basis (and it is).

I turned the breaker back on after my cleaning and made sure the fan would at least come on (proving power was getting to the unit) and it was indeed getting power. I set the wall thermostat for 70 on cooling and went fishing - I had to run a lengthy test of course!

I returned from fishing about 6:00 PM and the house was 77 degrees. Obviously we have an AC problem.
Some basic info: the house (and AC unit) is 16 years old. The problem is not gradual - the problem happened suddenly. No lightning strikes, power surges, nothing traumatic happened to the AC unit AFAIK. The fan turns, but the unit is blowing cold air out the top of the unit. Every outside the house/tent AC unit I've ever seen blows hot air out the top. The air coming out of the vents in my house is not cold, just pretty much room temperature.

So is it the condenser? The compressor? What could it be? Please weigh in with questions & comments.

 

[fishfryer]

I know what you're thinking - "don't sweat it dude!" Anyway yesterday evening the house was feeling a tad warm despite the inside wall thermostat being set at 70 in the "cooling" mode. But by bedtime the house was naturally cooling a bit so I put the heat on for 70. This morning (before I would need the AC of course) I checked/did some basic things on my outside Rheem AC unit, like checking for any broken or torn pipes, wiring, etc. I cleaned the one coil area that had some dust & debris. I changed the filter in my hallway ceiling near the thermostat that is supposed to be changed on a regular basis (and it is).

I turned the breaker back on after my cleaning and made sure the fan would at least come on (proving power was getting to the unit) and it was indeed getting power. I set the wall thermostat for 70 on cooling and went fishing - I had to run a lengthy test of course!

I returned from fishing about 6:00 PM and the house was 77 degrees. Obviously we have an AC problem.
Some basic info: the house (and AC unit) is 16 years old. The problem is not gradual - the problem happened suddenly. No lightning strikes, power surges, nothing traumatic happened to the AC unit AFAIK. The fan turns, but the unit is blowing cold air out the top of the unit. Every outside the house/tent AC unit I've ever seen blows hot air out the top. The air coming out of the vents in my house is not cold, just pretty much room temperature.

So is it the condenser? The compressor? What could it be? Please weigh in with questions & comments.

Not trying to be cute, but what it sounds like is about six thousand dollars. A 16 year old unit is running on borrowed time.

 

[oldfella1962]

Not trying to be cute, but what it sounds like is about six thousand dollars. A 16 year old unit is running on borrowed time.

so, the entire sets-on-the-ground outside AC unit may have to be replaced? Ouch!

 

[Milkman]

Heat pump or gas furnace?

 

[DOUG 281]

condenser maybe. I don't think they cost that much. IT would be worth a try hope you don't end up needing a new unit

 

[Lilly001]

I’ve had a capacitor go out, 150.00.
A reciever dryer ruse through and leek, 1000.00.
And a fan motor die, 1500.00.
Im sure there are plenty parts left to replace.
10 year old unit 8,500.00 when new (York).
With older units it’s often a loss v benefit decision.
I also had ants get caught ln a relay on the outside unit but I fixed that for free with a can of wd40.

 

[baddave]

can't nobody on here tell you what it is, we might can tell you 17 things it MIGHT be. I believe you gon have to call somebody

 

[oldfella1962]

Heat pump or gas furnace?

I have a Rheem gas furnace in my attic and (I assume according to my research that I just began ten minutes ago) that the indoor half the AC system sits on top of this furnace.

 

[oldfella1962]

I have a Rheem gas furnace in my attic and (I assume according to my research that I just began ten minutes ago) that the indoor half the AC system sits on top of this furnace.

One of the videos I just watched said that the capacitor (which I think is in the outdoor part of the AC system) goes out a lot especially during bad thunderstorms which occurred the night before my AC going out. But wouldn't it take a direct hit to do this?
Regardless, capacitors do go out eventually because I replaced hundreds on army electronics equipment over the years.

 

[jrickman]

If the compressor doesn't kick on at all, I look at the contactor first, because bugs have a tendency to get up in them this time of year, then the capacitor. After that, assuming I'm getting power to the unit, I call in the pros.

 

[Milkman]

It could be something as simple as the capacitor, relay, rat chewed a wire, fire ants in the contacts, etc.

It could be as major as a compressor or coil gone bad. Or perhaps a refrigerant leak. If it’s a R22 unit it’s going to be replacement time if it’s any of the items mentioned in this paragraph. If it’s a R410 unit it may be repairable.

The components mentioned are in your outdoor condensing unit.

A service technician is needed to properly diagnose and repair.

 

[basstrkr]

85% of A/C failures are electrical. 75% of those failures leave visual evidence.
Contactor is smoked, capacitor is smoked or swelled. Compressor connections melted or smoked.

Is the condenser fan and air mover fan both running.

Does it have condensate high level switch.

Can you push the contactor in and does the compressor start.

 

[Oldstick]

I agree with all the above. If your unit is NOT a heat pump then failure to cool when in cooling mode is something with the outside compressor not turning on or either a leak of the refrigerant somewhere that could be anywhere from the outside unit into the house where the cooling coils are located. Possible bad compressor or possible leak if you say the outside fan comes on normally

If a Heat pump that might be different as it is possible the outside reversing valve could be stuck in heating mode, preventing the switchover to cooling mode.

 

[GTMODawg]

I know what you're thinking - "don't sweat it dude!" Anyway yesterday evening the house was feeling a tad warm despite the inside wall thermostat being set at 70 in the "cooling" mode. But by bedtime the house was naturally cooling a bit so I put the heat on for 70. This morning (before I would need the AC of course) I checked/did some basic things on my outside Rheem AC unit, like checking for any broken or torn pipes, wiring, etc. I cleaned the one coil area that had some dust & debris. I changed the filter in my hallway ceiling near the thermostat that is supposed to be changed on a regular basis (and it is).

I turned the breaker back on after my cleaning and made sure the fan would at least come on (proving power was getting to the unit) and it was indeed getting power. I set the wall thermostat for 70 on cooling and went fishing - I had to run a lengthy test of course!

I returned from fishing about 6:00 PM and the house was 77 degrees. Obviously we have an AC problem.
Some basic info: the house (and AC unit) is 16 years old. The problem is not gradual - the problem happened suddenly. No lightning strikes, power surges, nothing traumatic happened to the AC unit AFAIK. The fan turns, but the unit is blowing cold air out the top of the unit. Every outside the house/tent AC unit I've ever seen blows hot air out the top. The air coming out of the vents in my house is not cold, just pretty much room temperature.

So is it the condenser? The compressor? What could it be? Please weigh in with questions & comments.

Sounds like a contactor, transformer or capacitor. I would start with contactors because you can make and break them with a screwdriver. If it was working and quite at once and didn't start acting up chances are its one those three and should be a inexpensive fix if you can find a reliable contractor who actually troubleshoots and does not just sell new units.

 

[GTMODawg]

One of the videos I just watched said that the capacitor (which I think is in the outdoor part of the AC system) goes out a lot especially during bad thunderstorms which occurred the night before my AC going out. But wouldn't it take a direct hit to do this?
Regardless, capacitors do go out eventually because I replaced hundreds on army electronics equipment over the years.

Capacitors can fail for a multitude of reasons and are generally undersized to begin with. Very common problem. They can definitely fail during a lightning storm but they also fail due to age and voltage variances and all manner of reasons. In a system that age it would be pretty common for them to fail because they were barely sized right to begin with and as the system ages the current goes up slightly....combine that with even a subtle drop in voltage which can happen hundreds of times a day without any sign will increase the current just enough to blow a capacitor. Very inexpensive item and easy to replace....not so easy to troubleshoot for most home owners. Best to just replace it with a similar sized one and at that age probably one listed as hard starting.

 

[K80Shooter]

Don't go messing around with something that you know nothing about. Yes, it's expensive but call a repairman. If you question what he says, then call another for a second opinion.

You messing around could wind up costing you a lot more in the long run.

 

[JustUs4All]

Yep, Over the course of my life I have turned any number of $50 problems into $500 problems by trying the repair myself when I knew full well that I wasn't qualified to do it.

 

[natureman]

I had one do that. Replaced the outdoor capacitor and all was fine. I think it was $125 to have it done. The repair guy could have said I needed a new unit and I would not have known any different. Nice to know there are some honest people out there.

 

[oldfella1962]

Don't go messing around with something that you know nothing about. Yes, it's expensive but call a repairman. If you question what he says, then call another for a second opinion.

You messing around could wind up costing you a lot more in the long run.

Preaching to the choir! I always defer to the experts when it comes to certain home repair issues, if only because your insurance may not cover you if something goes south and it was your fault. I just want to know as much as I can about the problem so I don't get ripped off/overcharged/etc. I have worked just a little with AC assisting AC guys in the company I worked for before I retired. Of course just enough to get myself in trouble if I tried it myself.

For example internet videos show how to clean the evaporator coils (inside the house part of the AC unit) but my coils are in a completely sealed up area attached to my heater. I don't mean just screws and nuts, I mean taped up and sealed up like Fort Knox, obviously not designed for the homeowner to perform any preventive maintenance. I'll ask the AC tech about that, whether it has anything to do with current problem or not. I always pick tech's brains when I can.

Sidenote my AC evaporator coil is an ALL STAR coil model AS36A264T and takes R-22 refrigerant.

 

[GTMODawg]

Don't go messing around with something that you know nothing about. Yes, it's expensive but call a repairman. If you question what he says, then call another for a second opinion.

You messing around could wind up costing you a lot more in the long run.

Amen. Not to mention even electricians get ate up messing around with capacitors from time to time....they are pretty dangerous. They can explode with some authority if tested or discharged incorrectly and can give you a NASTY shock if they aren't discharged correctly. That being said if a contractor tells you you need a new system you very well might but there is nothing at all wrong with getting several opinions on the matter. The HVAC industry is all about selling units. A good contractor can make as much or more on quality service calls like replacing contactors and capacitors but they can also make a lot of quick money doing replacements. Some are good and some are akin to a used car dealer......its a crap shoot. But if you are not comfortable and pretty knowledgable you can indeed cost yourself some time and money if you don't know what you are doing.