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Jethro Rocker

Jethro Rocker

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Have a plumber coming tomorrow but just asking around.
AC stopped tonite (humidex 38C) because the furnace fan has stopped. Fan tries to kick jn for like a second shuts off immediately. It's from 2008. I assume there is some sort of switch that can get stuck to turn off fan before it gets going?
Cheers
 
@LRT

I would imagine LRT might stop in possibly tonight yet, if not I'm sure he'll be around tomorrow. HVAC expert, he is.

Based on your description I might think seized/faulty blower motor or possibly hi/lo pressure switch? I dunno. I'm not an HVAC tech. Is there any other details you could give? Brand? Model?

Does it blow at all or just try to come on and then immediately stop? Are there breakers tripping? Does it make cool air at all or does the fan quit before it even has a chance to?
 
A common motor fail to start condition is a failed start-up capacitor.
Since the motor begins to start then stops it may be pulling too much current and tripping an internal auto-reset cut off.
Or the motor could be shot (windings shorted, going over-current)

but thats my armchair diagnosis from 2100 miles away, lol.
Im no HVAC tech but have worked on systems a bit over the years.

Hope you get it sorted quickly and without too much $$.
 
There's a good chance that the motor in your furnace is a ECM motor but in 2008 it could still be a PSC motor. If its an ECM motor then its likely that the modual is bad so there's nothing you can do. If its a PSC motor then there is a chance its a capacitor, fan relay, band control board, or bad bearing in motor.

If its a PSC motor then you could take like wires and go strait to the both breaker phases and make it run till a tech can come out.
 
All these things sound quite plausible. It starts to blow for like 1 sec then shuts off. So blower works to that degree but something is telling it to quit, it would seem. No indicator LED on board to say anything. Was actually OK in here last night with everything closed. It was a humidex of 38 C (100 F) yesterday here!

Thanks all! I wonder too about a thermostat or pressure switch or relay or such. Hopefully they have parts in town. Haven't seen dude yet... long weekend here. Better get it done today!!
 
If unit monitors static pressure you wou see an error cose with LEDs. Im betting the bearings are bad in motor. To check dont move shift in and out of motor but move it up and down or side to side. If it has play it needs replaced.

Question
How many wires come out of the motor?

ECM motor
20200731_120222.jpg
See the the number of wires

PSC motor

20200731_125645.jpg
 
I spent over 6 k on a new unit a year and a half ago -- it hasnt worked right from day one--

right now (a/c has been running full on since 11 am) its 82 degrees inside my house and 60% humidity ----I have another company coming next week to install all new larger (proper sized) duct work under the house--- which they say will FIX the problem ---------

I can tell you this if I find the owner of the company that put the unit in --- (its been a nightmare involving threats of lawsuit etc. etc. ) originally --- he will not see the following sunrise.
 
Jethro Rocker said:
Have a plumber coming tomorrow but just asking around.
AC stopped tonite (humidex 38C) because the furnace fan has stopped. Fan tries to kick jn for like a second shuts off immediately. It's from 2008. I assume there is some sort of switch that can get stuck to turn off fan before it gets going?
Cheers
Click to expand...
Sometimes it's just the lubrication in the motor which has dried out.
Then the motor won't turn, the static pressure won't rise, and the thing shuts itself off.
Take the motor apart re-lube and see if it frees up. That's what I think I would try.
 
Jethro Rocker said:
I'm not nearly that clever was just troubleshooting potentially.
It worked as soon as dude pushed safety button on front again. Didnt work last night, they are changing out the capacitor on the motor as apparently this can be fairly common. It is working, as long as it keeps doing so!
Thanks again guys!
Click to expand...
Duuuuuuuu ude! Awesome repair job.
 
Jethro Rocker said:
Amd I had nothing to do with it. I was just hitting up yoir brains in case the plumber came up with some weird crap. I didn't think so, he is a good dude but still...
Click to expand...
Do plumbers deal with HVAC stuff up north there??

I was an apprentice plumber for about two weeks a long time ago. I quit without even collecting my pay because the guy I was working for was a complete douchenozzle. One of the absolute worst people I've ever worked for and it was actually worth the money to me to never see him again, so that's what I did....all we did was install :poo:pipe though, mostly lol
No HVAC stuff...
 
Last edited:
mcblink said:
Do plumbers deal with HVAC stuff up north there??

I was an apprentice plumber for about two weeks a long time ago. I quit without even collecting my pay because the guy I was working for was a complete douchenozzle. One of the absolute worst people I've ever worked for and it was actually worth the money to me to never see him again, so that's what I did....all we did was install :poo:pipe though, mostly lol
No HVAC stuff...
Click to expand...
Oh yes. Heating plumbing etc. Mine is a really good guy. I really wanted to see here if general consensus was to replace the moter then I might have pushed that to prevent future problems, for example. Thx!
 
chilipeppermaniac said:
Oh yeah, and not to go above LRT and anyone elses experience, but can a clogged air filter also create a failure to blow, Ac condition as well? I seem to remember my dad's furnace or ac would not run right and all it was was a dirty filter.
Click to expand...
Absolutely. Filters need to be clean so as to get good airflow, or else the condenser coil behind the filter can't do it's job efficiently and sometimes it'll even freeze up solid into a block of ice. Then the only thing you can do is wait for it to thaw out while you're sweating and cussing at the A/C lol

I speak from personal experience, I have also neglected to change my filter lol
 
Amp Mad Scientist said:
Sometimes it's just the lubrication in the motor which has dried out.
Then the motor won't turn, the static pressure won't rise, and the thing shuts itself off.
Take the motor apart re-lube and see if it frees up. That's what I think I would try.
Click to expand...
On most indoor blower motors the bearings are sleave type oiling them will only temporarily fix the problem. If it gets to were the motor won't run from lack of lubrication then its best to replace the motor. If the motor has little plugs or oil tubes add a few drops yearly it will help to extend the life of the motor.

Air flow is key to airconditioning, if the filte is plugged or the indoor coil is dirty it will freeze up. One other thing I recommend to all customers is to take a garden hose and wash out the condencer/outdoor coils. A common problem i run into is that the outdoor coils are dirty causing a excessively high pressure. If the coils outside can't breat proper the refrigerant won't be able to remove enough heat to change the state from a super heated gas/vapor to a subcooled liquid. This is the basics of A/C. The indoor coil has a metering device that the subcooled liquid goes through into a low pressure coil. The low pressure coil causes the liquid to boil off and produce cooling by absorbing latent heat, this is heat found within moisture. As the refrigerant traveled through the coil it boils off till its a super heated gas in other words has absorbed its max potential of heat. Next it traveled to the outdoor unit and this is where that heat is removed. It travels through the outdoor coil as that heat is being expelled. As the proper heat is removed the state of the refrigerant changes back into a liquid and the cycle starts over again.

I'm basically saying to save the life of you equipment the coils need to be clean. Clean the outdoor unit once a year and change you filter monthly if its a 1" filter.

On another note if a tech has to come out yearly to add refrigerant then you need to make them find the leak and repair or replace whatever is leaking. Heating and air companies love the uneducated customer for this because it a quick fix to add refrigerant knowing that they will be back next year. Add 2lbs, charge there minimum labor and they were there for 20 minutes. In our aria our minumum laybor is 1hr at $110, most jobs i can do in 1hr or less so my average billable labor is 12hr in a 8hr day. I do try to find and repair all leaks so I dont have to return for the same problems. DO NOT let the tech put a stop leak snake oil in this WILL cause problems down the road.

Hope this helps for you guys to understand the importance of homeowner maintenance and also somewhat educates so a tech can't take advantage of the situation. It happens all to common here that tech bills a customer for things that didn't need or never were replaced
 
Our system is 2 yrs old as it had a refrigerant leak and was replaced. I keep the outside unit hosed off well like several times a season and the filter is clean. Thanks. That is something I do look at regularly. It sure is crankin now! As long as the fan keeps blowing, if the blower dies at some point I will get it changed.
 
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