Antifreeze Issues in Hydro-Air System
I have been noticing seepage from most all mechanical joints on my hot water furance. The system has two air handlers (one in attic) so it has antifreeze in it. My oil company says the seepage is typical of systems with antifreeze and there is not much I can do for it. Now, my system relief valve has developed a slow drip, and I am concerned that the system will gradually be diluted toward fresh water by the auto-fill valve. Approximately ~ 16 oz. leaks in a week.
Questions: 1) Are there special gaskets and components that are designed for use in antifreeze treated systems? 2) Should I be concerned with dilution of the antifreeze? 3) Is there a way to test if I have a problem with the antifreeze strength?
Thanks!
Replies
Greetings SHud,
As a first time poster Welcome to Breaktime.
This post, in response to your question, will bump the thread through the 'recent discussion' listing again.
Perhaps it will catch someone's attention that can help you with advice.
Cheers
half of good living is staying out of bad situations
I am not familiar with a glycol heating system, so I may be way off base here.
We have several cooling systems that use a glyco loop on the condenser side of the system. We have experienced some leakage at times, but that is not "normal." When the leaks have been located and repaired, we recharge the system with glycol and water, and check the specific gravity to make sure it is within spec.
You are right that just adding water will dilute the mixture to a point below the manufactures reccomended level. You can also go to far the other way. To much glycol can cause a ph shift and result in corrosion build up in the system.
Simply put, leaks are not normal. that is just BS from someone that doesn't want to be resonsible for bad work to start with.
Dave
I agree with you in that leaks are due to degraded seals or improperly joints. The leaks need to be repaired, the system flushed, passivated and re-filled with the proper mixture of a suitable propylene glycol product.
In N. IL glycol in heating systems is very common and boilers are quite compatible with propylene glycol. Ethylene glycol, ie.e the stuff that automotive antifreeze consists of, is not suitable for heating systems. One manufacturer of a full line of heating water products is Hercules. http://www.herchem.com/products/heatingproducts.html
ethylene and propylene are both available for heating systems.
The advantage of propylene is it safer if ingested. Backflow prevention is cheaper.
I've never seen ethylene glycol that was intended for a closed heating system, and I know that some boiler manufacturers specifically prohibihit its use if you should wish to have their warranty remain effective. Add to that a host of chemical incompatibilities and I can see no reason to ever put ethylene glycol in anthing without tires. Highly not recommended for use in hydronic heating systems
Sorry Tim, but this time you don't have all the facts.
Every commercial system we do is ethylene. Dow makes both. Only issue with compatibility is aluminum boilers.
Here is a great link on antifreeze and boilers.
http://www.raypak.com/afreeze.htm
Edited 5/31/2006 1:09 am ET by rich1
I see poor choices and poor installations all the time. Prevalence of poor practice doesn't change the fact that it is still poor practice. I do not consider ethylene glycol a suitable choice regardless of its availability or your use use of it. I understand your personal quote better now ;p. Seriously, though, I know there are certainly products available with which I am not familiar, so I will keep an open mind to the possibility that I have some learning to do on this subject. Weil-McLain, for which I was a distributor for the last 2 years, specifically voids the warranty of many of their boilers if ethylene glycol is used in the system. While I can't speak for all manufacturer's warranties, this is a fairly definitive reason for opting to use propolyne over ethylene in choosing a glycol product.
Ethylene Glycol tastes sweet and will kill your dog if he licks it. Given that leaks are apparently common, that should be reason enough not to use it.
Interesting. I think the issue with Weil is the ethylene attacking the seals between sections. Not many new Weil's being installed around here. Hydrotherms, Superhots,Slant Fin, Smith, Buderus, Viessmann,Trinity, Laars, Raypak. Don't know of any prohibitions on these, but I've been wrong before. :)
Wouldn't say that ethylene is a bad choice, just have to account for it in system design. ie; backflow prevention, pump sizing etc.
On a large system, it can be cheaper than propylene, less product needed for the same freeze protection.
Edited 6/1/2006 1:26 am ET by rich1
Thanks Tim.
As I mentioned, my only experience is with it is in cooling systems. We have two Liebert units with roof top condensers that use a glycol loop. Over all they have been very reliable units for the past 20+ years. I would estimate we have had fewer than 6 to 8 leaks at the condensers in that period. These are commercial units that run 24/7/365 for raised panel floor areas within our building. I don't ever recall a leak in the loop from the evaporator to the RTU durring that time.
When I hear anyone say "leaks ar normal" for any type system, my warning bells go off. I wouldn't be employeed five minutes after I tried that line on my boss, yet I hear residential intallers, service techs, and owners use it time and agian.
Dave
Edited 5/27/2006 9:35 am ET by DaveRicheson
I have a dual air-handler heating system, with one in the attic, such as yours. Because of the location, we also use anti-freeze.
There is some amount of seepage at various points, most noticably at valve stems and threaded plugs, probably more noticable because the anti-freeze doesn't evaporate with the water, but rather remains, as evidence. Seepage, not necessarily an active leak, appears to be somewhat normal, at least in my systems, and is more an indication of inadequate thread sealant or stem leakage than anything else, and what little is found has been developed over 13 years. Any active leak, indicated by dripping, is not normal and should be corrected.
"I am the master of my fate, I am the captain of my soul." Invictus, by Henley.
I have the same heating system with a second air handler in the attic. couple years ago there was a leak. my plumber drained the mixture into 5 gallon pails, fixed the leak, then added antifreeze to get back to the proper consistency and pumped it all back in.