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I published this elsewhere a few weeks ago.. should have done it here as well.

In hot weather like we're having now, it only SEEMS like your air conditioning is more likely to fail.

But lots of people are going to be more likely to pay for unnecessary repairs and replacement than usual because they can't bear the thought of losing their comfort.

Let me just say that this sort of weather will make membership in 'Angie's List' a bargain for those who have Air Conditioner problems. The reason being of course that those highly rated HVAC companies are less likely to do unnecessary work.

I've taken care of 40 plus older residential units for ten years and in that time exactly TWO AC systems have had to be replaced. Both were WELL over 20 years old.

It pays for you to know what your outside unit - the condenser - sounds like when it's running well.
Before a compressor fails it will start to make more noise/ get louder than usual, this may continue for days, weeks or even years. But do make a note of it. Chances of that compressor suddenly failing without warning -getting louder-are very low.


There are two common failure parts in the condenser:

The power relay called a 'contactor' and the motor capacitor{s}. When the AC suddenly quits working, odds are over 90% it's one or the other at fault.

If the capacitor fails, the fan and/or the compressor tries to run but cant get started.
- Retail price of capacitor: $25-$35

Tip: When a capacitor goes it usually, due to overheat, balloons to some extent. The terminals are on little plastic cups.
Sight along the tops of the cups; if they are not level with each other, it is gone.


The important numbers on a cap are the UFD ratings. Typical on a residential 24,000 btu condenser is 35 for the compressor and 5 for the fan. 370 vac is the voltage rating. You can sub 440 vac in a pinch or +- 15% for the ufd rating but I dont advise it.

If the condensor fan motor itself fails, it will be relatively hard to turn. It should react like a pedestal fan. Easy to turn.

With thermostat in 'Off' position, try to turn the fan with a ruler or thin wood piece. If it's stiff or hard to turn, the bearings are bad.. actually usually 'dry' but it may not be worth having it lubricated. It has sealed bearing and must be disassembled to do it. {handy car guys can do it, of course. I lubed a dry-bearing fan motor 7 years ago and it's still running.}

- Chances of fan motor failing electrically - almost zero. If it turns easily, and tries to start but wont.. chances of bad capacitor about 99%.
Retail price of fan motor: $150-$200.

If the outside unit does nothing at all, listen for a faint hum/buzz. That is the relay coil trying to start it. It is getting a signal from your thermostat. The A/C breaker may be tripped, in your inside box, the fuse {if any} in the outside box may be blown or the relay may be bad.
Cost - about 35 bucks. Most of them are the same. Difference is single or two pole switching.
- recommend you take a picture of it when you go for the replacement along with the make model and serial number of condenser unit. Swap one wire at a time.. with the power disabled at shutoff box.

  • If there's no hum, check to see if you can turn the furnace blower on by changing thermostat switch from 'auto' to 'on', your furnace breaker may be tripped or there's an electrical problem in your furnace controls.
  • Make sure the control wire between condenser and wall isnt damaged by a stray weed whacker.
  • If there is a hum, the compressor and fan do nothing, and your outside unit is getting power, that relay/contactor is probably bad. Common in ten year old or more.
Ice on lines to condenser unit. Means bad furnace airflow 90% or low refrigerant - not likely because it only happens at a certain point of low charge.
  • Change filter or your furnace blower is bad* or blocked air return registers.
  • If the outside lines have ice, that means your inside coil is a solid block of ice.
Turn heat/cool OFF, furnace blower 'ON' and allow at least 2-3 hours for ice to melt. You will likely have water puddling around the furnace when that's done.
Use cheap furnace filters in cooling season. The wet inside coil gets those little bits of dust anyway. and the airflow is better.

* If the furnace blower doesn't run, turn t-stat fan switch to 'on', open the access door and reach into the blower and see that it spins freely. If it does, push in the interlock - you may have to wait a while, and see if the motor hums.

If it does, carefully reach around and spin blower. If it then runs, the problem is 80% chance the capacitor. I have seen inside motor run windings fail.
 

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Speaking of this...it might not be a bad idea to build a metal cage around your outside AC unit...my parents just bought a small house in a very quiet lake community...it was a HUD foreclosure...two days after all the inspections, somebody stole the whole unit right off the concrete pad it sat on outside...just cut all the wires and lines and took the dang thing. The cops, and the real estate people thought that it was probably the HUD people or one of the inspectors...
 

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Wow, how timely this thread is. Thanks for the info.

We had the "Ice on lines to condenser unit - Means bad furnace airflow 90% or low refrigerant - not likely because it only happens at a certain point of low charge." problem.

Our current unit is 8 years old, and to put this nicely, is a "Homebuilder Special" Carrier unit; rated at 10 SEER. After having the lines freeze we had the unit inspected and refilled the refrigerant (1.5 lbs of R22). About 48 hrs later the system had leaked down again and the lines were frozen.

I called the vendor that I had done business with and ordered up a 16 SEER 2-stage Amana unit. I got a credit on the new unit for the cost of the previous service call. Intallation is scheduled for Monday.
 

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Discussion Starter #4
Wow, how timely this thread is. Thanks for the info.

We had the "Ice on lines to condenser unit - Means bad furnace airflow 90% or low refrigerant - not likely because it only happens at a certain point of low charge." problem.

Our current unit is 8 years old, and to put this nicely, is a "Homebuilder Special" Carrier unit; rated at 10 SEER. After having the lines freeze we had the unit inspected and refilled the refrigerant (1.5 lbs of R22). About 48 hrs later the system had leaked down again and the lines were frozen.

I called the vendor that I had done business with and ordered up a 16 SEER 2-stage Amana unit. I got a credit on the new unit for the cost of the previous service call. Intallation is scheduled for Monday.
I guess it wasnt timely enough. Did they even try to find the leak? Geez.. leaking down that fast.. That's like finding a hole in the wall in a hurricane for anyone with any skill.

I said it was a CERTAIN POINT of charge that will cause icing. It would look like a spike on a graph of the evap temperature. I'll explain how it happens if you insist but rather not.
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On the stealing condensers part. a couple months ago I had one delivered to the back door of a building, then I had to go get some supplies, I was gone half an hour and two kids came through the back yard and tried to carry the condenser away. Tenant saw them and they said they had an order to pick up the old unit and thought that was it. heh.
 

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Nope, never tried to trace the leak. They offered to put the AC equivalent of fix a flat in the system. I said no thanks.

No need to explain the nitty gritty details.
 

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Nope, never tried to trace the leak. They offered to put the AC equivalent of fix a flat in the system. I said no thanks.
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Well, after your warranty's over find a new company. Speaking of warranty:

The reason there are so many licensed HVAC contractors and so few gypsies is the industry warranty terms. Put it this way, there arent any givebacks for incidental failures, the installer eats the labor involved. The mfr pays only for the part that failed.

You'd think that since markup is 100% there would be lots of guys like me not in the biz {I do property maint} offering to do whole systems, cheap. Nuh-uh. I did a favor once for a broke friend when his heat pump failed. The new one failed a year later and the failure caused the compressor to burn out and the result is just like in a car. Except it's easier to just replace the whole system. but the mfr and dist only wanted to pay for the part that failed.

Fortunately I proved it was bad assembly design that caused the lesser part to fail and the physics that caused the fail.. of course they would have had others too so that helped. Eventually {three months} got the entire cost back.

But I had to eat all the time I put in on the replace. And the friend thought nothing of the effort I put in to get the money back for the replacement.

No longer friends as you would guess. So.. only a fool or a crook will do Gypsy HVAC system installs.
 

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Interesting. Yea, I figured there was something on the order of 100 % markup. But I'm sure all the companies are the same. Then you lump overhead, labor, permits, old unit disposal, etc. into the price. BTW, is there a market for reclaimed R22 ? I asked if it was worth anything to them to get what's left out of the old unit and they said they actually have to pay a disposal fee since the R22 must be reprocessed to meet purity requirements.

I know it's quite lucrative, one of the neighbors in the community has their own HVAC company and they're living a lot larger than I am. I went with a different company. I wasn't about to give them any of my $$$.

BTW, PM sent.
 

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Discussion Starter #8
Interesting. Yea, I figured there was something on the order of 100 % markup. But I'm sure all the companies are the same. Then you lump overhead, labor, permits, old unit disposal, etc. into the price. BTW, is there a market for reclaimed R22 ? I asked if it was worth anything to them to get what's left out of the old unit and they said they actually have to pay a disposal fee since the R22 must be reprocessed to meet purity requirements.

I know it's quite lucrative, one of the neighbors in the community has their own HVAC company and they're living a lot larger than I am. I went with a different company. I wasn't about to give them any of my $$$.

BTW, PM sent.
No the HVAC companies are NOT all the same. There's a pretty much standard markup and a pretty much standard labor rate but a big difference in the quote, anyway.
Sometimes I would wonder that a good part of the quote is their expectation of callback.

Come on! Dont like their face so you cut off your nose? I dont care if their dog craps on your lawn, they're a good bet to treat you right. Unless they dont like YOU.

Like I said in the PM. It's all in the service. The units are built with pretty much the same parts.
>>> ANGIES LIST!<<<
No I dont use Angies List, but if I were looking for that sort of big ticket item where labor skill is real imprtant like HVAC, Roofing or Windows I sure would.
 

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Good post. Just out of curiousity, how many times have you seen lightning damage to an AC condensor?
It's my understanding that this is pretty rare (especially when nothing else in the house is damaged).
And don't mind Trunk, he has money burning a hole in his pocket from all of that OT...;)
 

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Discussion Starter #10 (Edited)
Good post. Just out of curiousity, how many times have you seen lightning damage to an AC condensor?
It's my understanding that this is pretty rare (especially when nothing else in the house is damaged).
And don't mind Trunk, he has money burning a hole in his pocket from all of that OT...;)
Actually I cant recall ever..I dont think it happens a lot. There's little to no electronics in the outside unit*, that's all in the furnace and the steel cabinets and copper tubing make a good ground-distribution system against transients.

* any electronics woulld be a delay circuit to prevent run-stop-run short cycling.

As to MAJOR damage, that may be due to the capricious nature of ball lightning.
- one of those things people dont believe unless they witness it first hand. It can pass or go right through something it should destroy, just to destroy something you'd think would survive it. My cousin had it happen to him but no one would beleive him. It came in one window, out the other on the opposite side of room and set a vine trellis on fire.

BTW. The thread is also a request to look out for older folks that you know.. they get taken a lot on simple repair > system replaces. It's different when you have discretionary funds. Most olders dont.
 

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In a related note, here's a DIY someone posted on calguns.net about how to handle A/C maintenance.

http://www.calguns.net/calgunforum/showthread.php?t=319234

It's not much use to me (no A/C system) but I think it's pretty interesting. My first thought was that a cat had been sucked onto the exchanger.

-g
 

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Everyone I know that has AC every two years shell out 2400 after baking in house for two days, that is how they do it. This is on top of 400 dollar electric bills during the summer. Ouch.

I don't have AC, I have an evaporative cooler (swamp cooler, which with rain at night and 100+ degrees during the day the house is certainly a swamp), so other than a small 10k btu window unit in my office (which gets used about 4 hours a year) I get to muck out mineral buildup and mud and not clean evaporators or condensers.

I can't name the number of filters I have seen that are so packed with lint and dust that they passed hardly any air, it would start pulling from leaks in the return.
 

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Discussion Starter #13 (Edited)
In a related note, here's a DIY someone posted on calguns.net about how to handle A/C maintenance.

http://www.calguns.net/calgunforum/showthread.php?t=319234

It's not much use to me (no A/C system) but I think it's pretty interesting. My first thought was that a cat had been sucked onto the exchanger.

-g
heh... I see that all the time. But it's almost NEVER pet hair in the condenser.

It's cottonwood seed fluff

Inside a whole different thing.. disgusting.

The longer they stay there the more they mat and end up looking like cat hair.

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It'd be great if swamp coolers were an option in most places.. but I hear they dont work in Phoenix anymore and, depending on location, bet it's close to not practical in Tucson.

Kid in Albu-qwerky has one. It's uncomfy in monsoon. But not unbearable.
 

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We ran a can of leak sealer stuff in our unit a few weeks ago. I'm guessing it's about as old as the house. Still at adding r22 every week or so. At night we supplement with 2 or 3 portables.

Are there any brands you would steer clear of? I'm not doing a Goodman (reason is pretty long to explain....) but is there a middle-of-the-road unit to be had that's worth it?

Replacement isn't in the budget at the moment. We will need to run all new copper as we're moving from a 2 ton to a 4 ton when we do change.
 

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We ran a can of leak sealer stuff in our unit a few weeks ago. I'm guessing it's about as old as the house. Still at adding r22 every week or so. At night we supplement with 2 or 3 portables.

Are there any brands you would steer clear of? I'm not doing a Goodman (reason is pretty long to explain....) but is there a middle-of-the-road unit to be had that's worth it?

Replacement isn't in the budget at the moment. We will need to run all new copper as we're moving from a 2 ton to a 4 ton when we do change.
Interesting. I'm glad to hear that you and Mr.Brain are getting by doing your own maintenance.

The rule of thumb that was quoted to me is 1 ton per 600 sq feet of living space.

Do you have one or two units on the house now? We have two smaller units; one for the upstairs (2.5 ton) and one for down stairs (2 ton).
 

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You are the man....I have been thinking that maybe my compressor start capacitor is going out in my cheap window unit. Either that, or its the wiring in my house. Intermittently after it has run for a little while, the blower still runs, but it slows down and the lights on that side of the house go dim for about a second or two. It will do it again later. Finally, you can hear the compressor start running on one of those times. Thats why I suspect the capacitor. What do you think about the lights dimming though? Thanks!
 

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You are the man....I have been thinking that maybe my compressor start capacitor is going out in my cheap window unit. Either that, or its the wiring in my house. Intermittently after it has run for a little while, the blower still runs, but it slows down and the lights on that side of the house go dim for about a second or two. It will do it again later. Finally, you can hear the compressor start running on one of those times. Thats why I suspect the capacitor. What do you think about the lights dimming though? Thanks!
Probably both. I'd get on that. Locked rotor current is usually about 5x run current. So a problem with run phasing would be heavier current draw.
The failure sequence for a power cap is shorted first, then open. That's why the cans puff out. Maybe your cap refuses to 'fuse'.

On the other hand, it could be short cycling. If the refrigerant hasnt equalized since shut off, compressor has a problem overcoming head pressure.
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I just got a quote for the freon removal ($125) and disposal ($75) to fix my A/C. Does this sound right? I feel like I'm getting ripped off.
 

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Discussion Starter #19 (Edited)
I just got a quote for the freon removal ($125) and disposal ($75) to fix my A/C. Does this sound right? I feel like I'm getting ripped off.
Depends, among other things, on your particular failure.
{to me that GENERALLY sounds like they're charging 125 per hour to remove} But then they have a specific government mandated procedure to follow. That means they can charge you for it even though it is/was SOP and part of the bid before the mandate.

And location.

The disposal fee doesnt seem too bad; the company gets essentially nothing or negative from the reclaimer, but they got no choice. EPA sez so, doesn't that make feel safe? Here's their best case, bargain situation:
http://www.johnscrane.com/r22.html

It's not outrageous per se, but get another quote if that's applicable. Let me reiterate, I'm not in the retail service biz, but I know these guys have to cover their butts.
I have an alternative but I do cover mine as well, I ask for the guy's refrig certificate. but another reason I dont do gypsy work.
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You think THAT'S bad? Just wait till you get your quotes for replacing windows on your house!

Gotta protect the children, dont'cha know! :)
 
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