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Discussion Starter · #1 ·
Here's a recap of what's been done so far...
25 year old Lennox central ac.
Plenty of freon - tested ok.
Thermostat checked out ok.
Compressor wouldn't start - replaced contactor - no joy.
Replaced Transformer & relay in air handler - no joy.
Technician (who was doing me a favor) said it must be the 18/2 wire that runs from the attic out to the compressor. Haven't tested it yet.

I don't want to use the same technician again, he's did this as a favor
(I paid him $100). He works for an HVAC company as a field tech.

What's should I expect to pay to have an HVAC company complete the troubleshooting and get this clunker fixed?

Any insight from HVAC gurus greatly appreciated.
 

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Discussion Starter · #3 ·
New unit? - I hope not.

When this was first tested, the compressor started up when the contactor was triggered manually. It runs and cools fine. So this appears to be a control problem. The contactor isn't closing when it's called.
 

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Neighbor came over last evening and asked if I could look at his condenser unit, no cooling going on.

He say's: "I know you know about the wiring and stuff."

So I grab my meter and some tools and walk over. We pop the top and hand turn the fan. Very tight, as in tight dry bearings. Motor very hot to the touch (aka)hot windings. So I unplug the molex to the fan motor, connect my meter and turn on the disconnect, 240vac. Check ohms on the windings about 100 ohms.

Diag: Fan motor needs replaced feersur.............................

TroubleShooting time. 7.3 minutes.

Charge to a neighbor. $0.00:rolleyes:

Told him to call for a emergency service or sweat all weekend. He did and unit was up and running after replacement 2 hours later. Service guy did not have to troubleshoot anything, just replace the motor. Happy day for him.:clap:

Not bad for a Low Voltage Guy....... Huh????? Too bad I don't stock condensing fans I could have made a buck or two.:whistling

Les
 

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so 7.3 min later he's......still sweating........ i'm all for helping out, and even though time is money i dont mind nor often charge the neighbor or close friend for simple things, but if the problem isnt fixed and no offence to you, kudos on the diagnosis, then everyones time is wasted.
i dont understand HO obsession with cutting corners or thinking any excop fireman type(no offense civil servants, it's just a phrase) with a set of tools can do what a professional tech can. would he/she go to their friend the dentist to fix their backache because they were cheaper?
any schmuck can pull out and change let's say fuses. but do they know why they need to hacr/td fuses, or know where the max amp. is listed, or what made the fuses blow in the fist place. can they diagnose the original problem and not just bandaid the symptom? ok now thats out of my system, have a good weekend!
 

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so 7.3 min later he's......still sweating........ i'm all for helping out, and even though time is money i dont mind nor often charge the neighbor or close friend for simple things, but if the problem isnt fixed and no offence to you, kudos on the diagnosis, then everyones time is wasted.
i dont understand HO obsession with cutting corners or thinking any excop fireman type(no offense civil servants, it's just a phrase) with a set of tools can do what a professional tech can. would he/she go to their friend the dentist to fix their backache because they were cheaper?
any schmuck can pull out and change let's say fuses. but do they know why they need to hacr/td fuses, or know where the max amp. is listed, or what made the fuses blow in the fist place. can they diagnose the original problem and not just bandaid the symptom? ok now thats out of my system, have a good weekend!

Just like the old saying: Nice guys finish last. I have been last for a long time and most likely will be in last place till the day I die. It was 7.3 minutes at the end of my long day and a little time to talk to my neighbor.

BTW he was only asking me to look at it to see if it was something simple. It was not, he requested an invoice, I refused.

Today I replaced a kitchen faucet for another neighbor. Took a couple of hours to finish. 37 year old single mother of two boys. She bought the faucet I installed. As payment she invited me out to a local restaurant for dinner. I accepted........................

I have never had a neighbor, friend, family that has tried to abuse my capabilities and experience. If they did I would let them know very quickly or just explain the fee involved.

Glad your venting was good for you. Have yourself a good rest of the weekend as well.


Les
 

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Odds are, if they felt that the dentist could fix the back ache at a lower price, it would be considered. Price is always important. Not hating on anybody, just saying with you analogy, If somebody can get the job done for cheaper, one will consider using their services. It's always been that way.
 

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I will bet that the original condensing unit in question was one of those round carrier units (aobut manufactored in '85-88). I have run into a few of them where they have a bunch of controls in condensing unit. Fortunately, the schematic usually is not sun damaged, so it's not too hard to read, but that setup is a little more complicated than simply 24v to the contactor.
 

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why did you replace the contactor,relay and transformer. You could have verified if they wher working before wasting time and money.Dont just keep replacing parts till you find the broken one. Make sure you have 24v controll voltage at the contacor when you call for cooling, and go from there.
 

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why did you replace the contactor,relay and transformer. You could have verified if they wher working before wasting time and money.Dont just keep replacing parts till you find the broken one. Make sure you have 24v controll voltage at the contacor when you call for cooling, and go from there.
NOOB '101' fer sure...........................:clap:
Resurrected post for 2009.:laughing:
 

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Go to the tstat and turn on the "fan on" switch or button. If the blower runs, you have 24v. If not, check for 24v at the tstat or the indoor unit and correct that (Tripped breaker, open transformer, open wire, open control, open fuse- test for 24v shorts that burned transformer or fuse).

If that fixes it- your good.

If you have 24v;

Then Jump "Y" to "R" at the thermostat. If the condenser doesn't run, there is bad/open wiring, bad contactor, or a control in between not working.

If it does run- replace the tstat, or repair loose wire etc at the tstat.



I'll walk up to an outdoor unit that isn't running, place my ear to the case and listen for a hum. If it's humming but not running, it is whether 240v loss or the contactor not making contact. If it isn't humming, it isn't calling or the contactor is a rare one that doesn't make noises. :laughing:
 
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