6 Year old heat pump going on 5th acoil - WHY?

[hpacoil5]

Have 3 ton heat pump(6 years old)that has had a-coil replaced 4 times and now is failing again. Tech says that something (?) is causing corroision of copper joints which in turn allows escape of coolant resulting in "freezing up" of unit. This unit is in an upstairs bedroom closet. We have a 4 ton (same type of heat pump, same age)in the basement and have never experienced a failure. The outdoor units sit side by side... Any clue to what is going on here?

[dynalowrider79]

how old is the house. is it new or old

[hpacoil5]

House is 25 years old

[amd]

Are you storing any corrosive chemicals like bleach beside the air handler or near a return air vent?

Perhaps the problem was misdiagnosed and the leak is elsewhere.

[dash]

The only thing I know of is "Formicary Corrosion",might want to search on that.

It however is due to VOC's(Volitile Organic Compounds)which are found mainly in newer construction.Particle board,carpet,furniture,lots of things.

I've never heard of that many coil failures ,regardless of the reason.I'd be concerned that the leak is somewhere else,maybe even close to the coil.Not knocking the tech,but he could be mistaken,what has he told you about these repeated failures??

[hpacoil5]

With each replacement came a different "problem" from bad batch of a-coils to problems with sealing (?). Tech and so called specialist both say where air is passing over fittings there is corrosion and that "something" is causing this. The closet in which the unit is contained was made just for that purpose - so there is nothing in the closet but the unit.

[coordinatesales]

Where are the returns located for that system? I agree with above that a chemical near a return may be causing the problem. Hair saloons sometimes have corrosion problems due to the hair spray propellants being sucked in to the returns.

[rkious]

Does not matter if nothing is in the closet .... The return air is were the "corroision" is more than likly coming from . Return air can suck in bleach fumes , cat littler box fumes , sewer fumes or whatever . Even the water coming into the house can carry stuff with it that can eat the coil up . You can have the coil coated to prevent this.


Ross Kious

[rickboggs]

A lot of folks like to clear and treat their condensate pans and drains lines with bleach. I even watched the Weather Channel recommend this. A/C companies recommend this. Don't do it!

[hpacoil5]

Very interesting....thanks for the information. There are two air returns - one in the master bedroom and one in a spare bedroom that is rarely used. The master bath is relatively open to the bedroom. Is it possible that the humidity from 2 showers a day and fumes from cleaning products could contribute to this problem? Any cosmetic products (hairsprays, etc.)used are not of the aerosol varity. To my knowledge bleach is not used to clean the AC units...

[smokin68]

I'd be looking more closely at the lineset......Any pictures hung in it's path,any new siding/drywall installed,etc.?Probably can't see it entirely?

Is this the same company on all four coils?

[beshvac]

Under the right conditions, (i don't know if they exist in your situation) stray currents can cause accelerated corrosion. Is your furnace and heatpump properly grounded. I have seen a lot of installations where the ground wire is not hooked up.

[rickboggs]

on a water source unit, caused the heat exchanger to leak. And the copper water lines would develope pin holes.

beshvac, that's a good call.

[Edited by rickboggs on 07-14-2006 at 06:19 PM]

[The Penguin]

candles burning?

[RoBoTeq]

Anything that produces a chemical scent will affect the corrosion of your cooling coils as well as your heat system and your general health.

If you can smell a product, there is a chemical in the air. Chemicals such as are used to produce scents are extremely corrosive. Add to the chemicals a tight built home and you are basically poisoning your home with toxic fumes.

Stop using all scented products and you and your HVAC system will live better lives and last longer.

[hillbilly tech]

Dang Robo i learned a little something then,my wife burns them dang candles all the time.

[smokin68]

Originally posted by RoBoTeq


Stop using all scented products and you and your HVAC system will live better lives and last longer.




If you like smelling like an armpit......

[bmac]

I've never seen anything bad enough to ruin a coil in a year. Have they shown you the leak?

[hillbilly tech]

I'de have to see the leaky coils to believe it ,never heard of that,somebody geten who dood.

[RoBoTeq]

Originally posted by smokin68

Originally posted by RoBoTeq


Stop using all scented products and you and your HVAC system will live better lives and last longer.




If you like smelling like an armpit......

Nope. It is a lot easier to find and eliminate the source of offensive odors when they are not being masked. Also; a lot of chemically scented products and most products claiming to reduce odors have chemicals in them that simply desensitize the noses ability to smell. That is why so many people who use massive amounts of smelly crap cannot tell how strong the odor is.

[markj]

The only thing that I have seen that can ruin a coil that quickly is sulfur water. Sulfet in the air will attack anything copper. How does your water smell?

[sean scully]

I agree with all the above, next coil change go a new line set and better yet replace the complete system and be done with it. I'm sure it would be cheaper. New technology has improved the energy efficency enough to make it pay off in the return on investment.

[rickboggs]

beshvac said,

Under the right conditions, (i don't know if they exist in your situation) stray currents can cause accelerated corrosion.

In my case, the water coil (heat exchanger) failed in 2 yrs. And copper water supply lines failed every yr. They had two units but only one had this problem.

My wife found the smelly soure in our house.... me. I'm just not easy to get rid of.

[RoBoTeq]

Originally posted by markj
The only thing that I have seen that can ruin a coil that quickly is sulfur water. Sulfet in the air will attack anything copper. How does your water smell?

All chemical aromatics contain suphites.