Anti-Freeze in Boiler??

Feb 03, 2008 9 Replies

My oil company has suggested putting anti-freeze in my boiler to avoid the possibility of freeze-ups. It sounds like a good idea, but I was wondering if anyone has ever done it and how did it work??



Specifically, does your system heat the same?? That is, does your home get warm as fast, and do you use the same amount of oil/gas/whatever with anti-freeze as with water??



Anyone have any real life direct actual experience with this??



Thanks!


If you have areas of your system subject to freezing, you should have it installed. There's nothing uglier that frozen broken pipes in the winter, especially if no one is home at the time.

Keep in mind I don't know a lot about hot water or steam heat.

You say you have a boiler. Could that really be a water heater? Boiler would infer (in my limited knowledge) a steam heating system. If so then I would guess you would have a special antifreeze different from the automotive anti-freezes I know.

If it has the same qualities as automotive anti-freeze, I believe it would increase the boiling point and therefore the temperature of the steam. That could cause problems and/or increase the effective capacity of the distribution system. It would also mean for either hot water or steam systems the efficiency would increase somewhat as it improves heat transfer and it helps reduce corrosion.

And if it ever hits the flame via a leak it will burn if it is Ethyl Glycol based such as car antifreeze suggest you insulate the pipes or find a new plumber. If electric unit fine not gas

And if it ever hits the flame via a leak it will burn if it is Ethyl Glycol based such as car antifreeze suggest you insulate the pipes or find a new plumber. If electric unit fine not gas

It's antifreeze made specifically for hydronic boilers

The bad news is that using glycol in your boiler reduces the efficiency by 15%. Also, if your system is kept up to pressure by your household water supply, you have to have a special backflow preventer called a RPZ valve (this is true in my town--check with your local plumbing inspector) which has to be inspected annually by a qualified person. Otherwise you will have to have a closed system which will have to be brought up to pressure periodically. I personally wouldn't do it unless I had some area prone to freezing (like a garage or a sidewalk) or I left my house unattended frequently during the winter.

Water is more efficent than car antifreeze at transfering heat, it will lower boiler efficency, If you put 100% antifreeze in your car the interior heater core wont warm you as well, in the summer the motor will run alot hotter. Why should your pipes freeze.

Actually I understand that water is more efficient than water, but the mixture is better than either by itself.

It all depends on what brand boiler you have. The newer boilers use O-rings as a seal to connect the boiler sections together. They are susceptible to a lot of things that can harm them. The old boilers had steel nipples pressed together to join the sections. Not much hurt them. Get out your instruction manual and see what it says. If you cant find it, contact the manufacturer. Bubba

In the automotive field ethylene glycol has the reputation of leaking through places where water won't. Given a perfectly sealed system, it might not be important, but could be inadvisable in older equipment. HTH

Joe

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required