My Water Furnace Superheater now leaking...and so are others

Our home was built in Aug. 2006 and a Water Furnace Geo unit was installed. My brother built a home, right across the road, 4 years prior and had the same company, same unit installed. Approx 5 years after each unit was installed, each of the desuperheaters have started leaking. The heating/ac company says it is the water source and has had testing done on the water, lab work done on the copper tubing and the pipes are corroding from the inside out...but no real answer as it what is doing it. The water tested on the 'hard' side. Heating/ac company says other customers on this rural water source also have issues, no issues with town or well water...The owner of the heating/air company has had to replace his own desuperheater 3 times in the last 12 years!

Water Furnace has told the heating/ac company that nation wide they've had no other issues with the desuperheaters except in the region where we live.....And of course the units warranty is up

We even installed a whole house water filter and water softener when my brothers unit started leaking, hoping we would avoid such issues. No such luck apparently (we had water in the basement last night surrounding the geo unit.

Basically I'm getting the run around....heating/ac company and Water Furnace says it's the water....water company says it's testing fine, nothing abnormal.

What are my options...other then replacing the desuperheater every 5-6 years! And why would it corrode...does the water not circulate all year long in the desuperheater or does it sit stagnant in the pipes....I read somewhere that the desuperheater doesn't work much in the spring and fall...I’m wondering now if it started corroding this fall, while it wasnt working much....then when it started working more this winter, the high water pressure caused it to burst.
Any thoughts would be much appreciated.


Tony

 

That's the first I've heard of such a problem. We install desupers on all our geo jobs, though we are a fairly low volume firm.

I doubt a softener or filter would improve the water chemistry related to corrosion - it sounds like a pH problem

If your desuper is plumbed like most it "sees" full house pressure year round, typically 40-60 psig The circulating pump, which likely adds only a pound or so more pressure while it operates, runs only when the compressor runs.

Are you served by a municipal system and thus have a backflow preventer? If so, operation of your finishing water heater may be increasing system pressure substantially when the finishing tank operates, owing to thermal expansion. A small expansion tank is recommended to mitigate the problem.

 

Thank you for your reply....Yes, there is a small expansion tank located right above the holding tank water heater. The best answer I'm getting from the company who installed it is "We're sorry, we know it's a pain, we've spent alot of money trying to figure out why the desupers are corroding in your area, your options are to A) replace it every 5-6 years when it corrodes again B) don't hook up the desuper and run your geo thermal without it." According to them, WaterFurnace doesn't have an answer either. It's very frustrating to think we will need to spend hundreds of dollars on our system every 5 years or so....we are leaning towards not hooking it up.....obviously that decreases the efficiency of our system....but does anyonw know how much?

 

In the business for years and never seen or heard of this. Interesting that you can now get CuNi heat exchangers for geo heat pumps (which recognizes the potential for trouble) but you can't get a CuNi DSH.
I don't think the DSH save you enough to justify out of warranty replacement. Get a heat pump water heater for probably less money and call it good.

 

Actually it increases the efficiency of your geo. You may experience elevated operating cost, on your hot water but depending on cost/kw, numer of users etc. Op cost difference could easily be much less than $100/yr.

 

beckman1367,

We apologize that we have not responded earlier. It is our understanding that you and your contractor are working with our Consumer Relations department towards a resolution. If you need additional assistance, please feel free to contact them.

 

I work as an hvac tech / supervisor. I orderred my 2008 Carrier GTPX with more expensive cupra nickel heat exchanger coils because they are supposed to resist corrosion. (At least that's what the books say). (My system is open loop)

When I worked with W.B. Guimarin in Columbia, and Charleston, one time I saw that a manager at a Charleston apartment project substituted cheaper copper coils for the orderred cupra nickel geo heat pumps in an apartment area with brackish water. (He then pocketed the difference in money "saved", to make a quick fortune). Lawsuits followed as the copper heat exchange coils began quickly failing 3 years later.

I actually am dealing with my own current leak issue on my own unit.

Seriously, I would have a commercial chemical company test my water and tell me just what I have. (You are paying for the testing and recommendations). What you don't know is what you don't know. If you have a corrosive condition you either need heat exchangers of superior metal quality that will "hold up" or use a secondary indirect purer / non reactive water source. I do not want to speculate here without hard facts.

Almost absolutely pure water like I have in Lexington, SC can be on the acidic side of the ph scale. Under such circumstances standard residential copper piping will pinhole at 25 years.

If you have a condition condusive to corrosion, you have to deal with it if you are running open loop. Closed loop is easier, because you can simply pay a few dollars more and truck in water that is known to be neutral, and even if it wasn't, any chemical company can add minor chemicals to a closed loop system to make sure that it is and will remain neutral as the system is purged during installation.

You can also autopsy the defective coils (assuming they are not in warranty)

Do understand that if you orderred your geothermal system with the extra desuperheater coil that water ALWAYS runs through it whether it is productive in preheating water or not. This is because all brands that I know of in residential tonnage run the heat exchange coils in series.

A water control valve such as the orange slow opening Taco is always installed on the outlet side so that the coil is always submerged in water and exposed to as little direct oxygen as possible.

It is a tricky question to answer. Is is quality control or "asking for it" by tough water conditions. That's why it is helpful to know what kind of water you have.

Good Luck.

 

Nice post. I am sure you will get more information than you need.

I know water is the universal solvent.

I tend to want closed loop systems, and have been known to import "good" water to do them.

No one ever wants to admit they have made a mistake, which is why one needs to return warranty covered parts,

 

I am also having a problem with the desuperheater leaking on a waterfurnace manufactured geocomfort 4 ton split system. This unit was purchased in the fall of 2007, and has just developed a leak inside the unit in the desuperheater. The leak has gotten worse very quickly and required the plumbing to the desuperheater to be turned off until a resolution is found. Has Waterfurnace resolved this issue for you yet? I am in the process of contacting the manufacturer to see what can be done. I know the interior of these units are a combination of high voltage, high pressure, and water, which makes me concerned to see this type of interior leak...

 

Waterfurnace will only advise you to contact GeoComfort.

Bergy

 

Correct GeoComfort would be the only company with liability/responsibility in this case. Relabler's i.e. GeoComfort, Comfortaire, Carrier etc. hold all legal responsibility for the product regardless of who made it for them.