Read in the journal about lines freezing from boiler. I know of a few people that run a mix of rv anti-freeze in their system and have not had any problems. Its alot cheaper than regular boiler anti-freeze compared to 55 bucks for 5 gal bucket that I pd. I was told by one installer that rv was all he ever used and has never had a problem. He says biggest problem with outdoor boiler is acid eating out firebox in 8-10 yrs ,even stainless steel! have a Merry Christmas!

Actually, it was not the main line from the boiler that froze, just the feeder line off the main line to the shop.

Putting anti-freeze in the type of boiler I have is a big no-no! Voids the warantee and is a sure fired way to disaster.

Once I get a different zone valve in and the water in the feeder line can constantly circulate, then no more problems. Just waiting for the valve to come in.

-John