Trane HVAC problem. Honest service pros help!

[antiqueshell]

My folks A/C stopped working yesterday. A 17 y/o Trane unit.

The unit was inspected just this past May by the heating and air company they use to do bi yearly inspections.

A couple of years ago the service tech opened the service panel in the furnace where the coils are located and mentioned that the coils looked to be in excellent condition and there was almost NO dust in there, but the guy said he was going to clean them anyway just to make things optimal. LOL

Unfortunately I noticed that previous to that cleaning the year before and earlier the air was working very well, after the cleaning I noticed that the air at the register was NOT QUITE A S COLD but still within specs. I didn't mention this to my folks because I figured that I was noticing something unimportant and I was over reacting....

Now the current tech claims that the coils are heavily rusted and corroded. So for 15 years those coils are in tip top shape, but in just two more years the coils are a corroded rusted mess???
I think that the other tech sprayed that coil cleaner in there but never properly rinsed it off, causing the corrosion and failure...does that make any sense?

This current tech claims they can replace those coils for 1200 or of course they can buy a new unit for 4000$.

Suggestions or opinion would be greatly appreciated. Thanks!

 

[skyactiv]

Read the info in this link: http://www.goodway.com/hvac-blog/2012/08/hvac-coil-corrosion-should-you-be-concerned/

 

[Rand]

what exactly do you think he sprayed on it?

nothing he should be using would corrode it.

 

[antiqueshell]

Originally Posted By: Rand
what exactly do you think he sprayed on it?

nothing he should be using would corrode it.


Unfortunately I was not there, BTW my folks are elderly now in the early and mid 70s..

According to my Dad a couple of years ago when the tech pulled the access panel on the furnace end he actually commented on how clean the nice the coils looked, (Dad uses a 3M 7-8 MERV filter) but he was going to clean the coils with a product just make things optimal. So essentially for 15 years those coils were rust free, clean, and free of corrosion...now two years after the coils are supposedly cleaned they are a rusted and corroded mess?
That doesn't pass the smell test for me. Seems odd.

Actually some of the commercial products note that you must throughly rinse off the product to make sure it won't corrode. But then again who knows what that guy used. My Dad is NOT mechanically inclined like I am so he wouldn't think to ask too many questions...

A little more info...so no blower fan, (A/C unit fan working as normal) Dad checked the line at the A/C unit and found frost on the lines which means there WAS refrigerant in the system but the blower was not working. Makes sense because that mean no air to move and frozen coils and lines. Correct?

I wonder if it is just a faulty capacitor on the blower fan and thse guys are taking advantage.

 

[jrustles]

The coil cleaner is caustic. We used to spray clients EXTERNAL coils with the stuff and it literally eroded all the oxides away in minutes, at which time you rinsed it off. The spray would often catch a wind and mist would land on your skin or eyes and it burned. Not sure if the tech used that on the evap, anything's possible. Yes, if he left it to dry, a prolonged erosion period would follow and subsequent slow wash off with the condensate in normal use.

I'm not saying that's what's going on, it is 17 yrs old, but y'know I share your suspicions. Some of these guys are told to sabotage parts for business from their managers. I've known of techs routinely damaging high limit switches for a quick job

 

[Reggaemon]

First of all there are two types of coil cleaner that I use, one is corrosive and must be rinsed off a couple of times to be safe and a second type that does not clean as well but it will not eat the coil if the rinse is not done properly.
Now about that blower motor,if you got 18 years of service from that motor thank your lucky stars because that is way above their average life. I think the motor is done. In over 20 years I only came across a few capacitors that went bad.
If you have the right meter you can test the capacitor.

 

[antiqueshell]

That was might though exactly.

That the guy just sprayed the stuff on probably told my Dad that the condensate would rinse it off!

Again this is the internal coils inside the blower access panel near the furnace. What makes me darn suspicious is that the guy claimed that when he inspected it the coils were generally clean and free of dust and in good condition, (15 years of service) and then suddenly within 2 years they are a complete corroded mess. I smell a rat.

I told my Mom to ask Dad to get the repair order for that visit a couple of years ago and ask this new tech just what was done at that time.

Folks are sometimes frustrating because I have good general understanding of most mechanical things (basic logic) and yet they still don't bring me over when these repair guys come to
"work on" the home. LOL

If I would have been there a couple of years ago I would have told the tech if it looks great why mess with it, put the panel back on and be done with it.

 

[antiqueshell]

@Reggaemon:

That is my thought since the lines were frozen yet the AC unit fan was operating normally but the blower motor was not working. I agree that the motor is my suspect, unfortunately I am not over at the house, and my folks had the tech over earlier to "check" things out.

It would have been my first question to the tech.

I would think the A/C unit itself and the refrigerant was at an acceptable level if the unit fan was operating as normal, correct.

My parents believe in letting the pros handle things..well they are being "handled" in my opinion.

A little more info, this tech says he is going to add refrigerant to help them "get by" until they get a major repair or replacement . Funny because the stuff hadn't all leaked out if the line were all coated with ice, yet now supposedly it has a major leak. Hmmm.

 

[Reggaemon]

A major leak equals no refrigerant. I think that HVAC tech is handing out some [censored]. An old unit like this can be a little low on refrigerant but I don't buy the add refrigerant to help get by.

 

[antiqueshell]

I'm glad to hear you agree, but also annoyed too. That was my biggest suspicion, too. Unfortunately my folks are stubborn and don't want my help for some reason, but it isn't because they are old, they have ALWAYS tended to be like this. Heck you have a mechanically inclined person to question things but they just won't have it. Too independent for their own good.

I was actually staying at their home while they were away on vacation and the unit seemed to be working decently (recorded a 14-15F degree difference between ambient room temp and register closest to the furnace coil unit) I didn't notice any decline in temp cooling performance the entire two weeks I was there, only thing I did notice was that the blower motor seemed to vary a tiny bit in speed on a rare occasion and it seemed a bit louder than I previously remembered it, from a year earlier. But otherwise nothing out of the ordinary.

Oh, and I would like to sincerely thank all you guys for taking
the time to give your input. Cheers!

 

[Mackelroy]

I think your talking about the evaporator, contrary to popular belief , they tend to freeze up with frost and ice when coolant gets low from a leak and they are constantly running as a result, and the evaps can corrode. There was a big issue with them on various makes a few years back, new ones are copper with tin coating I believe to reduce corrosion issue. But yeah they are about $1200 to replace.

 

[antiqueshell]

@Mackleroy:

What's odd is that this refrigerant leak suddenly happened out of nowhere, it was operating perfectly up until yesterday with NO decrease in performance over time.

I supposed we could conclude that the leak "suddenly sprung" when a corroded pin hole opened up on that horribly corroded evap coil though.

The rat I smell is how likely is it that a set of evap coils stay in perfect shape for 15 years, and then coincidentally within two years after a cleaner is applied the same coils are a rusted out corroded mess. That seems waaaay too coincidental.

 

[michaelluscher]

Originally Posted By: antiqueshell
@Mackleroy:

What's odd is that this refrigerant leak suddenly happened out of nowhere, it was operating perfectly up until yesterday with NO decrease in performance over time.

I supposed we could conclude that the leak "suddenly sprung" when a corroded pin hole opened up on that horribly corroded evap coil though.

The rat I smell is how likely is it that a set of evap coils stay in perfect shape for 15 years, and then coincidentally within two years after a cleaner is applied the same coils are a rusted out corroded mess. That seems waaaay too coincidental.

......cleaner can be used wrong, as most of them are slightly acidic, hence there brightening ability. I suspect not thorough rinsing, or a too high concentration of cleaner/water hence a corrosive action.

I'd question the person that did this, and if the evidence is solid, hold them liable.

 

[antiqueshell]

Originally Posted By: michaelluscher


......cleaner can be used wrong, as most of them are slightly acidic, hence there brightening ability. I suspect not thorough rinsing, or a too high concentration of cleaner/water hence a corrosive action.

I'd question the person that did this, and if the evidence is solid, hold them liable.


That was my suspicion, that is why I was hoping that my Dad still has the repair order for the spring "check up" that was done a couple of years ago. Would the corrosion that occured from acidic chemicals have a specific characteristic that we could look for?

Also I mentioned earlier that I noticed that following the evap coil cleaning that the system seemed not to be cooling as well as it did prior years (seemed 3 -5 F warmer at the register than I perceived priviously) . I wonder if the tech bent over the fins in there as well when he was possibly scrubbing the coils. LOL
Of course you are NEVER supposed to touch those fins! I'm going to ask my Dad what he can remember from then. I have a great memory for [censored] like this, I totally remember when my Dad told me about the tech doing that odd cleaning a couple of years ago IMMEDIATELY when my Mom called me today with the "bad news". That was the first thing I thought about.

 

[michaelluscher]

http://www.nucalgon.com/products/coil-cleaners/condensers

Are the most popular for the trade Condenser/Evaporator cleaners IIRC

http://www.nucalgon.com/assets/prodlit/3-239.pdf

A chart of the products and there characteristics

If he mashed down a lot of the fins, that will reduce efficiency
If only a few, a coil comb isn't expensive, combine that with a coil cleaner used correctly, should restore it to good health for a good few more years.
If the corrosion has well and truly ruined it, then hold them liable.
Get some good pictures in, and gather all the documentation that you can.

Don't touch/mash the fins YES!, but not cleaning/rinsing them NO!.

This isn't one of those, "Don't touch it, it's working fine" kinda things, Akin to our Old ATF change it or not paradigm we face on le oil forum. Done correctly, cleaning will improve efficiency, It's that former part that people, so called "Professionals" seem to struggle with.........

 

[OneEyeJack]

I had a Rheem unit in my first home. I had the company come out every year and service it and when it wore out I replaced it within a 20 year period. During that time there were various charges for minor stuff and adding refrigerant. In my next home had another Rheem unit installed and did not sign a service agreement because of problems with the installation and did not like the people that did the work. I finished a lot of the work myself. I installed an electronic filter that is serviced by me, frequently. I did nothing to it and at 14 years I created my own problem installing a new thermostat. I shorted out the blue wire and blew a fuse in the unit. I called a local family owned company and they found the fuse problem that has me stumped and replaced it and also checked the pressures. They said everything was fine. I'm not sure letting an unknown person mess with the unit every year is worth the risk.

 

[SteveSRT8]

Originally Posted By: michaelluscher

......cleaner can be used wrong, as most of them are slightly acidic, hence there brightening ability. I suspect not thorough rinsing, or a too high concentration of cleaner/water hence a corrosive action.


This is true. I have a bottle on the shelf, it is acidic in nature. But in any normal ac unit it would be rinsed by condensation on the coils of the unit.

Something does smell a bit funny, but even with multiple filters the coils should still get dirty after 15 years...

 

[antiqueshell]

Originally Posted By: SteveSRT8
Originally Posted By: michaelluscher

......cleaner can be used wrong, as most of them are slightly acidic, hence there brightening ability. I suspect not thorough rinsing, or a too high concentration of cleaner/water hence a corrosive action.


This is true. I have a bottle on the shelf, it is acidic in nature. But in any normal ac unit it would be rinsed by condensation on the coils of the unit.

Something does smell a bit funny, but even with multiple filters the coils should still get dirty after 15 years...



I do recall that following that service I mentioned where the tech cleaned the evap coils there were a few cold days and the heat was likely on! Probably dried the cleaner on there before it could be rinsed off...

One other thing, I would guess that the A/C unit would have a pressure switch that would turn the compressor off itself if the refrigerant level was low enough, correct? In our case the A/C unit itself (compressor and fan) at least according to my Dad was operating as normal, only the blower fan was not running.

 

[rshaw125]

You need someone to check the blower motor. I would call someone different that has a good reputation and just tell him it's not blowing. Forget about all the other happenings. Get a second opinion.
17 years is not that old. I have a rental condo and the AC system is 39 years old. Not that efficient but it still works without complaint from the tenant.