Stove in Out Building

It's a long read, but good article Greg. Yup, Auto anti freeze toxic, boiler not. I do see they're making some nontoxic auto anti freeze now.

Auto anti freeze is better in many ways.The old stuff at least.It has lube in it for a cars water pump and if you only put a little(+15F) you won't see any differance in it's heat handling ability.It also used to have rust inhibitors for cast iron blocks.The NT anti freeze is corosive to start with and turns more acidic as time goes on(they recomend changing it every 5 yrs).I'm a plumber so was my father and my grandfatherWhen gramps had a beach house on LI and used prestone in the boiler.When we changed the boiler in the 80's(needed a bigger one when we added on)there was NO rust in the boiler after 32 yrs.The B&G 100 circulators were in great shape and we used them over.Gramps always used a 50/50 mix(-20F) in the system.We had a seperate gas water heater so there was no danger of it mixing with DHW in the coil.YMMV
DON

If you have city water and your back flow fails you could potentialy put toxic anti freeze into the public water supply. That's the reason it's not allowed in boilers. Even if you have it in a system with a hot water coil you won't get it in your domestic supply. Domestic water at 40 PSI and boiler at 20 PSI won't allow anti freeze into the domestic if the coil leaks.

If you are working on the DW and shut off the house. DW 0 presure heating system 15 lbs.= NG.I forgot to mention we used to fill the system with a double end(washer hose) purge system and remove hose when done.
DON

Good point Don! Yup, best just to use non toxic & be safe. It's no fun to be blind...or liable!

Well I do like to lean towards being safe,, but who drinks the water from the hot water tap?? The only way a person could get poisoned is if the domestic hot water coil leaked, or in my case the plate heat exchanger. The water in the boiler is at a maximum of 15 psi, [usually about 5psi], if it developes a leak, the house water pressure is going to over pressurize the boiler,, and blow off the pressure valve..

And if for some wierd occurance, and the house water pressure somehow got to be lower than the boiler pressure,, then the only water contaminated with glycol would be the hot water,, and I don't drink water from the hot water tap,, or drink water from the shower head...

IF I was going to add newly purchased antifreeze,, I'd go with the non-toxic stuff,, but I'm certainly not concerned about my system with automotive glycol.

Greg L

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LsFarm wrote:Well I do like to lean towards being safe,, but who drinks the water from the hot water tap?? Greg L

With a single lever faucet the hot and cold water mix. So you could get some hot water mixed in as you fill your drinking glass. While a lot of things need to go wrong for you to be poisoned, it's always best to avoid the problem by not using a toxic anti-freeze. There are some other bazaar circumstances that could push domestic hot water out the tanks cold water inlet.

Well I have decided on a Kestoker KA-6. I plan on running the Kestoker in a series with my oil boiler. My question is if I have an outage in my coal boiler and the oil kicks on and takes over will the hot water running through the coal boiler be enough to keep the DHW coil from freezing.

coalboy wrote:Hi to every one.when I decide on what coal boiler I am going to buy. I plan on putting it out in a 8x10 cement out building I have, about 20 feet from my house.My Question is. what precautions can I make to prevent freezing of water lines if I have an outage if i'm away from home when it happens.

Yes, that is what happens in my system,, the propane boiler would keep the coal boiler's water warm. My circulator pump runs full time,, so it will depend on how you set up your boilers in series..

Greg L