A/C question // Residential condenser unit [SOLVED]

[Tex Koder]

Any HVAC guys here?
Got a question for ya..

So the outdoor condenser unit's fan turns on and runs (seem normally)
and the interior blower moves air, but it doesn't seem to be blowing Cold air.. (we set it to 69°) room temp at 76°.

What I've done so far to remedy the problem:
1. Scrubbed & Clean the intake vents.
2. Vacuum the return air duct and replaced old air filter with brand new one.
3. Thought it might be the capacitor(s)..
But there's only one that I can see.




So if the fan kicks on ,does it mean the compressor is bad?

Trane XL 16i

Any feedback on what I should check next would be greatly appreciated.

 

[DLK83]

If it's low on freon, it could cause the compressor not to come on, it has a low-pressure cutoff switch similar to automotive a/c systems... could also be what is currently wrong with mine which is a thermal expansion valve... mine is plugged so the system ices up almost immediately and won't produce cold air, which reminds me... it's starting to finally warm up here, I should probably get on that

 

[gv21]

Bump to assist a solid AF member

 

[jkflow]

Not an HVAC guy but..
The capacitors are only for the fan(s), those are not your issue. Both fans are running.

Either compressor or just low on coolant. Coolant low implies there is a leak somewhere.
Could also be an electronic issue detecting low coolant or such but I would bet on low fluids.

Compressor would typically make some weird noises if it's going bad.

Mine is now 21 years old...pushing it, new HVAC units are now in the 20k range and going higher

 

[Bustedaw11]

Not an HVAC guy but..
The capacitors are only for the fan(s), those are not your issue. Both fans are running.

Either compressor or just low on coolant. Coolant low implies there is a leak somewhere.
Could also be an electronic issue detecting low coolant or such but I would bet on low fluids.

Compressor would typically make some weird noises if it's going bad.

Mine is now 21 years old...pushing it, new HVAC units are now in the 20k range and going higher

20k?

Someones getting ripped off!


Have you checked the A coil?? Last issue I had was a dirty A coil.... You'll have to pull the blower motor out and look up. If that coil gets dirty (and they do over time) it won't blow cold.

 

[RCSid]

I replaced mine last year with Ruud Units (exceptional).
1ea 2ton and 1ea 3ton. They were $5500 and $6200.
IDK a lot about HVAC, but @DLK83 gave sound advice. Youre best to have them looked at and go from there. AC/Refigeration is one of those things that you need someone that knows what they're doing, or you're just grabbing at straws. That unit looks like it's maybe 8-10yrs old. Mine were from '85 just running with low efficiency (like 60%).

 

[Tex Koder]

20k?

Someones getting ripped off!

No Doubt!!
I think That's Commercial HVAC pricing!

Or, somebody who has 11,500+ sq ft of living space..

That ain't me.

Have you checked the A coil?? Last issue I had was a dirty A coil.... You'll have to pull the blower motor out and look up. If that coil gets dirty (and they do over time) it won't blow cold.

How Dirty is dirty?

 

[Bustedaw11]

No Doubt!!
I think That's Commercial HVAC pricing!

Or, somebody who has 11,500+ sq ft of living space..

That ain't me.



How Dirty is dirty?

Well... I wish I could give an easy answer to that question. The air traveling over those coils is what cools the air going into your home. So if the coils are dirty the air won't be making contact with the cooled pipes that make up the coil. If you don't know what they look like it's very much built just like a radiator in a car.

I try to think of it about like your cars air filter. A little is normal and ok but when it starts covering most and or building up its time to clean it.

**I am in no way an hvac guy**
I'm a mechanic that tends to diagnose and fix problems myself before paying someone else to do it for me. This a coil being dirty is a common thing I was told about by an hvac friend of mine. I pulled my blower out to investigate and sure enough it was dirty. Cleaned it all out and the ac blew ice again.
I'm not saying this is your problem but I am advising that it is a simple and often over looked problem that can easily be handle by you.

 

[Tex Koder]

Well... I wish I could give an easy answer to that question. The air traveling over those coils is what cools the air going into your home. So if the coils are dirty the air won't be making contact with the cooled pipes that make up the coil. If you don't know what they look like it's very much built just like a radiator in a car.

I try to think of it about like your cars air filter. A little is normal and ok but when it starts covering most and or building up its time to clean it.

**I am in no way an hvac guy**
I'm a mechanic that tends to diagnose and fix problems myself before paying someone else to do it for me.

I'm the Exact same way.
I rather do it myself ,with my own two hands.
It's not rocket science.

This a coil being dirty is a common thing I was told about by an hvac friend of mine. I pulled my blower out to investigate and sure enough it was dirty. Cleaned it all out and the ac blew ice again.
I'm not saying this is your problem but I am advising that it is a simple and often over looked problem that can easily be handle by you.

Thank you sir.
I appreciate you sharing your experience and info.

I did kind of dug around the blower while up in the attic... It was way too HOT up there so I didn't stay too long.

Vacuumed around the filter area..
and took the 1st panel off just to see what's what -was mainly the blower and control circuits.
The 2nd panel housed what looked like the gas heating tubes.
Guess the third panel housed the coils.. which I didn't get to...

I'll have another crack at it tomorrow morning-ish while the attic temps are still bearable..

Hopefully that's the issue.
Fingers crossed.

 

[332_RC]

When it's running & the outside & inside are 'on' does the front of the thermostat have a 'cool on' light? If it's flashing, not static, then something in the system is not satisfied. Does your thermostat need batteries or is wired directly to the outside unit? Have you had power outages, storms or lightning? If the outside fan comes on but then goes off after a few minutes, the pressures on each side are too great or unequal. Either the pressure switch or the control panel circuit board inside the outside unit may be bad. The cover on the outside unit may have a diagram in there showing which lights on the control board should be lit up while everything is running properly. If one of the little lights aren't on, one thing isn't satisfied causing it to limp mode, freeze up, or time out. If the freon is good & a pressure test is good, could be the control board has gone bad from power outages. I had mine replaced recently because of this. The relay had been replaced couple years ago. The entire HVAC system was all brand new in 2012. First try turning off the thermostat, switching off the breakers to the outside & inside units, wait 5 min, try again. If it still does it, may be the outside control board.

And check the filter. My HVAC guy said don't use the fiberglass filters. They are too restrictive & cause pressure issues & too much amp draw on the blowers. I don't use those or the paper ones. I have the aluminum frame high flow, washable filters. Not cheap, but worth it.

 

[WoodiE]

Your air handler unit (in your attic) would also have a set of evaporator coils, which can greatly impact the efficiency of the unit. Have you cleaned, or have had the unit cleaned the yearly?

Otherwise the next place I'd check is to see if you have a leak and if the unit needs to be recharged.

 

[LibertyMKiii]

As others mentioned it could be a few different issues but likely related to the compressor, pressure switch, or refrigerant charge.
Probably will be best to get a reputable AC repair person out there. It sounds like it should be an easy fix since everything is turning on and blowing air.

 

[morrjr71]

I had a similar issue three times on the home I rented for ten years: it turns out each time the capacitor was bad. The capacitor starts the motor on the compressor, and if the capacitor is bad, the compressor won't start. The bad capacitors didn't physically look bad, but when the HVAC guy tested them they were bad. New capacitors solved the issue three times.

 

[Hector_Fisher]

Agreed, get a service rep out there to recharge your system with refrigerant and do an inspection. I'd bet it's just low.

 

[KnowAir]

I had the same issue last year. Everything seemed to be running, no cold air. Turned out the compressor was not running. You should be able to hear it, they make a pretty distinct noise. You can also tell if the compressor is running by feeling the copper lines that run in/out of the unit. One should be cold, the other gets warm.
I ended up replacing the capaciror and timer relay board on my unit. Back in business.
Mine is a 25 year old Miller unit.. when they say things ain't made like they used to be, they aren't kidding. That thing is a gem compared to the Chinese garbage we're buying today. Parts too.
She's a noisey old girl, but loyal.
If you don't feel cold/hot tubing while it's "running", then the compressor is not running. I would start with replacing the capacitor myself. All the numbers appear to be legible on yours, mine were not, another indicator of were quality is these days I feel.. good luck brother!!

Agreed, get a service rep out there to recharge your system with refrigerant and do an inspection. I'd bet it's just low.

Ay, I do ALL my own stunts. 12 years in my house, never a service call to anyone, well, except the septic guy.. I'm not that handy!!

 

[jamesbea]

I would place a vote for the capacitor as well. I have done this a few times over the years and it fixed the problem all until the very end of the unit. My death blow ended up being the coils in the unit in the attic (just like yours) had rust that caused a freon leak & caused those coils to leak. Unit was so old we could not purchase replacement coils. I won't go into the details of the niagra falls of water when the coils decided to defrost....

For my unit, the capacitor was only like $75. I was willing to roll the dice & try that before a service call, much cheaper. One time our downstairs unit went out in the middle of the summer while I was gone for a work trip. My wife called a service person to come out. Ended up being the capacitor & they charged like $300 to replace, which as you know from taking it apart is a super simple job.

 

[Mike'sGN-Kraton]

Went with a 24k btu Fujitsu mini split system a couple years ago, Three inside units... Winter I can get my house to 85 In a matter of minutes!!! Summer 64 is no problem!!! I'll actually find the cats snuggled up under the blankets!!! Mike

 

[LibertyMKiii]

Went with a 24k btu Fujitsu mini split system a couple years ago, Three inside units... Winter I can get my house to 85 In a matter of minutes!!! Summer 64 is no problem!!! I'll actually find the cats snuggled up under the blankets!!! Mike

Having multiple mini-splits is the way to go.
They have em on Amazon now pre-charged. Stupid HOA wont let us do them in a visible spot so I have to get creative in hiding it. I want one for the garage and master bedroom.

 

[KnowAir]

My outdoor unit went "pop" a couple years back.. wifey and I were outside doing some yard work. AC kicked on, snap,crackle pop..WTH? So I ran inside and shut it off. Turns out "Jerry" had made a nest in the electronics bay of the outdoor unit! Jerry got fried,LOL. Shorted out a wire in the process..which I replaced and it ran fine afterwards.
Another time my compressor wouldn't run it turned out to be the spade terminals corroded off at the compressor. They sell a repair kit, sweet!! Got her fixed up.
One of these days it'll surely be a major component though.. I keep a 12k BTU window unit on hand "just in case"..

Having multiple mini-splits is the way to go.
They have em on Amazon now pre-charged. Stupid HOA wont let us do them in a visible spot so I have to get creative in hiding it. I want one for the garage and master bedroom.

I thought about those, some local HVAC companies have been touting them. I guess there's some rebate or other from the GOV for installing them. What I wasn't interested in though is a unit hanging on the wall of every room. Since we have forced hot air, I didn't think it worth while to run all the wiring and plumbing through the whole house. Besides, it relies entirely on electric, which is essentially controlled by big brother. No thanks to more overreach..

Edit, Sorry, I went a lil sideways there..

 

[332_RC]

And fire ants are attracted to the current & the copper in the relays. GOOGLE:ants attrached to copper relays ac
''People also ask
Why are ants attracted to my AC unit?
In some cases, ants may use the outdoor components of an HVAC system as a way to invade a home, as they're often attracted to electrical currents. This sort of invasion is more than a simple nuisance—it can cause the entire HVAC system to stop working if too many dead ants accumulate in the outdoor components.''