Quick AC ?

[Knoxtnhorn 6184]

The capacitor is out on our upstairs unit.  I won't have a replacement until tomorrow afternoon.  The AC downstairs is less than a year old and in good shape.  Would I be doing irreparable harm by running the downstairs unit for 36 straight hours?   

[MonkeyDoughnut 10487]

I'm in Houston... and you're telling me A/C units actually turn off?                 Seriously though, yeah you're fine.

[Quagmire 2147]

You just reminded me to have extra capacitors on hand

[davidg 4042]

You just reminded me to have extra capacitors on hand

Get a fan motor while your at it. Maybe a contactor too. $200 fan turned into a $500+ service call over a weekend a few weeks ago for me.

[Knoxtnhorn 6184]

Got to be the capacitor.  The unit runs fine with a little assistance from my screwdriver to get the fan going.  Once it gets to the right temp and turns off, I have to spin the fan again.  It ran just fine all night; turned back off this morning.

 

[MonkeyDoughnut 10487]

16 hours ago, davidg said:

Get a fan motor while your at it. Maybe a contactor too. $200 fan turned into a $500+ service call over a weekend a few weeks ago for me.

on point... I had a 20yr old unit stop working all a sudden.. thought for sure was capacitor... had one of those but it was ok... I checked off everything and fan motor was problem.  Found one on ebay for $200... figured worth a shot considering otherwise was looking at $9k+.... 1 hour changeover and working better than ever.

[Jkwellborn 6898]

You won’t hurt your AC by running that much over the short term. You might wind up freezing it up though.

Make sure you discharge the capacitor after you unhook the wires. Those things can fuck you up.

[luke duke 6420]

Everyone should have a spare capacitor on hand. It is the most common failure point on an A/C and it’s such an easy thing to replace.

[Jkwellborn 6898]

Everyone should have a spare capacitor on hand. It is the most common failure point on an A/C and it’s such an easy thing to replace.

It’s probably the most common issue that isn’t related to a leak.

[Nice Guy Eddie 13569]

If this is the catch all question thread, here’s mine.

Old AC system with a Nest thermostat. A couple of times per day, my AC will cut off because it appears to have lowered the temp to the right level. 5 seconds later it starts back up. Could the Nest device be controlling that or is it more likely some other component shut down in its own and the nest tells it to restart? Anyway to test?  This doesn’t occur with every cycle.

[Dbeasy 15296]

12 hours ago, Jkwellborn said:

It’s probably the most common issue that isn’t related to a leak.

How can I learn to test and replace a capacitor myself? I have a five year old unit and the A/C people who came out for a standard yearly checkup said the capacitor reading was low, indicating it’s going to go pretty soon. I felt like they were full of shit so I want to learn how to do basic repairs myself if I can. 
 

And I have no idea how to discharge a capacitor, to give you a sense as to my knowledge starting point  

 

 

[MonkeyDoughnut 10487]

1 hour ago, Nice Guy Eddie said:

If this is the catch all question thread, here’s mine.

Old AC system with a Nest thermostat. A couple of times per day, my AC will cut off because it appears to have lowered the temp to the right level. 5 seconds later it starts back up. Could the Nest device be controlling that or is it more likely some other component shut down in its own and the nest tells it to restart? Anyway to test?  This doesn’t occur with every cycle.

Goggle "Nest short cycling", apparently it's a known issue with Nest controllers.

C wire not being hooked up correctly combined with the tolerance on Nest being just 1 degree they say, which in this heat will change very quickly. Either way, quick on off will ruin a compressor in no time.

[MonkeyDoughnut 10487]

5 minutes ago, Dbeasy said:

How can I learn to test and replace a capacitor myself? I have a five year old unit and the A/C people who came out for a standard yearly checkup said the capacitor reading was low, indicating it’s going to go pretty soon. I felt like they were full of shit so I want to learn how to do basic repairs myself if I can. 
 

And I have no idea how to discharge a capacitor, to give you a sense as to my knowledge starting point  

 

 

YouTube is your friend. It's very easy BUT follow all safety checks as it is dangerous if you don't, especially discharging the capacitor.  Also know when you turn off the disconnect (or breaker) for the ac that the wires from the thermostat will still have low voltage running through them (if you don't power off thermostat itself which isn't typically done).

https://youtu.be/i8nDBZo6XyE

[Jkwellborn 6898]

How can I learn to test and replace a capacitor myself? I have a five year old unit and the A/C people who came out for a standard yearly checkup said the capacitor reading was low, indicating it’s going to go pretty soon. I felt like they were full of shit so I want to learn how to do basic repairs myself if I can. 
 
And I have no idea how to discharge a capacitor, to give you a sense as to my knowledge starting point  
 
 

Normally, you can look at a capacitor and tell it’s bad. It will be swollen, particularly at the cap. You can buy a tester for them or use a meter, but to be honest, I think I’ve only seen one or two in my life that weren’t swollen noticeably when they were bad.

If the compressor is humming, but not running, look at the capacitor for it. If either fan is trying to turn and won’t, but will spin after you give it a little help, look at the capacitor.

When you change one, take a picture of how the wires are on there. Use a pair of insulated needle nose pliers to remove them. Take a screwdriver and put it between the contacts and touch them at the same time. I always did that a couple of times for piece of mind. Once that’s done, swap it out with a capacitor that is either the same or really close.

I’ve never tested one to get a reading. Maybe it’s a thing but it seems like a waste of time. Go ahead and grab one or two spares to have one hand for when it does go out.

[luke duke 6420]

If you want to be everyone’s favorite friend get this universal capacitor that will work in almost every unit. Use it in emergencies and swap it out after you have a chance to order a normal one.

https://a.co/d/7jpPgfm

[Quagmire 2147]

I remember the first time I had a capacitor go out , was able to buy one and fix it before the ac guy came out , when I called and cancelled and told him what I did he sounded pretty bummed he’d didn’t get to fuck me over.

[Nice Guy Eddie 13569]

43 minutes ago, Quagmire said:

I remember the first time I had a capacitor go out , was able to buy one and fix it before the ac guy came out , when I called and cancelled and told him what I did he sounded pretty bummed he’d didn’t get to fuck me over.

You know the AC guys love those calls. Get their minimum service call fee plus a high markup on the capacitor.  And the home owner is so happy that it doesn’t require an entire new system they happily pay the $300 invoice.  Of course that doesn’t stop the sales pitch for a new system.  “The entire system could go out tomorrow or next year”

[NeverMarryAStripper 22070]

My mom has three units.  They are each a self-contained unit that's on the roof of her townhouse, so there is nothing in the attic.  All three units were replaced 13 years ago, and they had to be lifted to the roof with a crane.  The upstairs unit quit working a few weeks ago, so I called someone to come out and take a look at it.  His diagnosis was a shot compressor, and he recommended that the entire unit be replaced.  Of course, he also said since all three units were the same age and needed a crane to install them, she might as well replace them all.  His estimate was $46K.  After I said thanks but no thanks, I called a second guy to come out. The second guy's diagnosis was a bad thermostat.  He replaced the thermostat, and it's been humming along fine since then.  He also told me that he could replace all three units for a fraction of the other guy's estimate and to give him a call if they ever really needed to be replaced.

[fattyflattie 4639]

1 hour ago, NeverMarryAStripper said:

My mom has three units.  They are each a self-contained unit that's on the roof of her townhouse, so there is nothing in the attic.  All three units were replaced 13 years ago, and they had to be lifted to the roof with a crane.  The upstairs unit quit working a few weeks ago, so I called someone to come out and take a look at it.  His diagnosis was a shot compressor, and he recommended that the entire unit be replaced.  Of course, he also said since all three units were the same age and needed a crane to install them, she might as well replace them all.  His estimate was $46K.  After I said thanks but no thanks, I called a second guy to come out. The second guy's diagnosis was a bad thermostat.  He replaced the thermostat, and it's been humming along fine since then.  He also told me that he could replace all three units for a fraction of the other guy's estimate and to give him a call if they ever really needed to be replaced.

Fwiw, I have a 60-ton hydro on rent right now for 180/hr, with 4 hr min.  Fuck that dude and his want for a new S-class. 

[T’Boo Ted Marshall 2759]

On 7/30/2023 at 5:41 PM, NeverMarryAStripper said:

My mom has three units.  They are each a self-contained unit that's on the roof of her townhouse, so there is nothing in the attic.  All three units were replaced 13 years ago, and they had to be lifted to the roof with a crane.  The upstairs unit quit working a few weeks ago, so I called someone to come out and take a look at it.  His diagnosis was a shot compressor, and he recommended that the entire unit be replaced.  Of course, he also said since all three units were the same age and needed a crane to install them, she might as well replace them all.  His estimate was $46K.  After I said thanks but no thanks, I called a second guy to come out. The second guy's diagnosis was a bad thermostat.  He replaced the thermostat, and it's been humming along fine since then.  He also told me that he could replace all three units for a fraction of the other guy's estimate and to give him a call if they ever really needed to be replaced.

There is always someone that will do it cheaper.  There are plenty of times we get beat by competitors but I know the margins they are accepting to do a job. I'm not willing to do a job below X% profit margins.  More often than not, they have much lower overhead and the owner is doing the work himself, but come warranty time he's hard to get hold of.  

Now the offer to replace all 3 when only 1 was "needed" was nonsense.  

[Dbeasy 15296]

I was messing with my thermostats trying to decide whether to swap them out for a smart thermostat. I decided not to, but I noticed that neither thermostat had the battery in it for backup power during a house power outage. 

I was about to put in the batteries but saw an online note that AC repair people purposely don’t put in these batteries because they can screw up the AC units. 

We want to have battery backup because we’ve gone out of town several times when power went out. The power outage screwed up the thermostats and the only way to get the AC units back on temperature control was to manually reset them. But because we were out of town, we couldn’t do it. 

Can we add thermostat batteries without creating some sort of AC problem?

[MonkeyDoughnut 10487]

I'm confused. Are you asking if you should put like the 9v battery in the backup battery slot designed into your thermostat by the thermostat company?

[Jkwellborn 6898]

I was messing with my thermostats trying to decide whether to swap them out for a smart thermostat. I decided not to, but I noticed that neither thermostat had the battery in it for backup power during a house power outage. 
I was about to put in the batteries but saw an online note that AC repair people purposely don’t put in these batteries because they can screw up the AC units. 
We want to have battery backup because we’ve gone out of town several times when power went out. The power outage screwed up the thermostats and the only way to get the AC units back on temperature control was to manually reset them. But because we were out of town, we couldn’t do it. 
Can we add thermostat batteries without creating some sort of AC problem?

Never heard of that.