Antifreeze

[muleman51]

Its just about time fire up the boiler again. Last year when I was gone for a week my lines to the house froze. I got them thaws after some work but don't want that to happen again. Can I use regular automotive anti freeze, I can get it in bulk barrels, so it is some what reasonable My system probably holds 80 gallons and is an open system. Or should I just buy boiler antifreeze. thanks for the help. Jim

 

[charly]

For some reason I read that you can't use automotive anti freeze.. I know there are issues using antifreeze,, less heat transfer and if you heat your domestic hot water you have to watch that you have it isolated that it can never get into your hot water. Also any fill valves for the boiler water have to have be a one way check valve that the antifreeze can siphon back into your drinking water line.. I'm sure others more involved with boilers can tell you more... Sounds like you lines aren't buried deep enough... Also keep your pump going... Any way you can back heat your water a bit with your regular heating system.. like just keep it at 40 degrees or so? I believe you have to use a non toxic anti freeze... Just think about what you'll have to deal with when flushing your boiler ever.. Lots of antifreeze! I always just ran water when I had one... all my chemicals came from Boiler Solutions.. I think antifreeze can also break down Orings in valves over a period of time as well.. My self I would try to stick with water and address the freezing situation on different terms..

 

[mustash29]

Do not use automotive antifreeze, toxic if it gets into your domestic water system, no safe place to drain it if needed without recovering it all and it's not the best for corrosion protection.

I work at a power plant. We have an 18,000 gallon propane tank for auxillary heat needs and it also fires the heat up / aux burners on the boilers. We have a propane vaporizer. 20 psi propane goes through an atmospheric (vented) water bath propane fired boiler to ensure it stays a warm gas during times of high propane draw.

The plant was built in '95. Our first and second vaporizers have rotted through the water jackets. We are in the process of getting the 3rd one shipped. Our water chemistry rep told us to not use automotive antifreeze. He recommended Dowfrost. That stuff is expensive, but it is safe for you, the environment and the boiler.

 

[woodsmaster]

Moving water wont freeze. I wouldn't go antifreeze unless I was going to be away often for long periods of time.

 

[heaterman]

Automotive = Ethylene Glycol. Very toxic, no additives for the type of use and materials found in boiler/heating systems. Will become acidic in an open system and wreck a bunch of stuff.

Boiler = Propylene Glycol. Non toxic or at least less toxic. Contains additives to extend the life of things like pump seals, gaskets, pumps and most grades are compatible with any metal found in a boiler system including copper, iron, aluminum, stainless, etc.
Less likely to become acidic but in an open system you will need to monitor the water chemistry and adjust when a sample indicates the need for a "tune up".

A few recommended brands..... Hercules Cryo-tek100. No-Burst from Noble Chemical, Rho-Gard from Rhomar(aluminum safe)

 

[charly]

I read a while back a post on here that said you should always keep your water moving in an open system even when the boiler is not in use... Keeps particles from settling in the corners and corrosion starting... when I had my Woodmaster I never shut it down for 7 years.., just for maintenance.

 

[Nofossil]

Moving water can freeze - it's sort of like hardening of the arteries. A bit collects on the surfaces, narrows down the passage, then floating bits eventually clog the remaining opening and you have a myocardial infarction. Or a frozen pipe.

On the other hand, moving water has a chance to pick up some heat from whatever structures are on each end of the buried line. That should hold off freezing for a long time, though it might likely cause massive condensation problems.

 

[woodsmaster]

Moving water can freeze - it's sort of like hardening of the arteries. A bit collects on the surfaces, narrows down the passage, then floating bits eventually clog the remaining opening and you have a myocardial infarction. Or a frozen pipe.

On the other hand, moving water has a chance to pick up some heat from whatever structures are on each end of the buried line. That should hold off freezing for a long time, though it might likely cause massive condensation problems.

learned something new. I was always told it wouldn't freeze.

 

[Bob Rohr]

learned something new. I was always told it wouldn't freeze.

Automotive = Ethylene Glycol. Very toxic, no additives for the type of use and materials found in boiler/heating systems. Will become acidic in an open system and wreck a bunch of stuff.

Boiler = Propylene Glycol. Non toxic or at least less toxic. Contains additives to extend the life of things like pump seals, gaskets, pumps and most grades are compatible with any metal found in a boiler system including copper, iron, aluminum, stainless, etc.
Less likely to become acidic but in an open system you will need to monitor the water chemistry and adjust when a sample indicates the need for a "tune up".

A few recommended brands..... Hercules Cryo-tek100. No-Burst from Noble Chemical, Rho-Gard from Rhomar(aluminum safe)

Automotive antifreeze is blended with silicates and will sludge up the small wet rotor circs. Stick with hydronic fluids.

Many of the automotive antifreezes are now propylene glycol. Preston Lo-tox and Sierra are a couple brands, but still not correct for hydronic applications.

Buy the fluid pre-mixed or blend it with demineralized water to assure a long life.

It's an expensive fluid to purchase, use it only at a last option. Pump size sometimes needs to be increased when you use glycol, it's tough to circulate especially when it is cold.

 

[charly]

learned something new. I was always told it wouldn't freeze.

I would keep it simple and just try to back heat your boiler if and when it needs to be kept from possibly freezing..

 

[BoilerMan]

^^^^^^^^^^^^^^^^^^^^^^^^^^^^
What he said! Unless you are gone for long periods of time and don't have a fire going, just keep the circulator running and introduce a small amount of heat back through your plate heat exchanger, assuming you have one.

TS