running piping to outside garage

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New Member
Nov 4, 2007
Blairsville PA
I want to heat my garage with my logwood indoor boiler. I want to run insulated piping unground to my garage radiators. Has anyone ever done this before???
two issues solved charge the system with RV type antifreeze and insulate the crap out of the pipes I would add an extra step place then in sewer pipe the seer pipe will protect the insulation from ground contact and lengthen it from deterioration
There are several companies that make the insulated pipe in different styles for outdoor use between buildings. Check with your local plumbing supply to see what they carry in your area. Its a great idea to protect the pipe and insulation from the ground water using drain, sewer or water pipe. All the local sewer and septic guys in my area use foam board insulation cut and placed over / around the pipe to add extra insulation.
i seen many different companies selling this insulated tubing, i made my own out to boiler site lots of insulation used. i did see a nice product from central boiler were they have a insulated protected piping that can be left out in the elements for people with owb until they know were the best place for their boiler is. this pipe can be put in ground later if needed. the outside of the piping or tube it is in looks to me as a mine belt material if you know what that is"very tough stuff". i would look on their web site . hope this helps. ryan
For antifreeze my pal that does HVAC work said they use boiler antifreeze and it's sold at Menards in gallons and 5 gallon sizes for about 12.00 to 15.00 a gallon
Definitely use heating system antifreeze--not the automotive stuff.
I used Thermo-Pex from Central Boiler. Two warnings:

1)Sit down before you ask them how much it costs
2)Do not expect to make curves tighter than say, 179deg with this stuff!!

Having said that, if you want convenience, this stuff is slick.

Just wondering the reasoning on this? The seals on a circ pump aren't too much different than a automotive pump I assume.

Did some googling and it seems to only be the toxic issue. Backflow preventers are pretty cheap and are used for other systems with ethylene gylcol connected to potable supply.

Eric Johnson said:
Definitely use heating system antifreeze--not the automotive stuff.
ISDBTU: Is that Janine Pirro in your avatar?

I think it's a code violation and if you have a spill of some sort, it could become a haz mat concern, especially if the line goes underground and extra especially if there's a well nearby.

Me, I wouldn't want a domestic water supply connected in any way, backflow preventer or not, to a hydronic system containing automtive glycol. But I know people who do it, and they're not dead or blind yet.
This is a good case of the conflict between all-fits-one code vs. educated decisions left to the individual. You really don't want toxic backflow in your potable water. Of course, the only way that could happen is if A) your backflow preventer valve failed, and B) your house water pressure dropped below your boiler pressure. Pretty unlikely combination, but possible.

I don't use antifreeze, but it would be safe if I did. Here's why: I have a shutoff valve between my house water and my hydronic system It's only ever open if I'm standing there charging the system.

I did it that way because I don't want a leak to go undetected, but a side-effect is that I could use toxic coolant with no risk.

Even with a failsafe system, I'd look at codes before doing something that could make long-term problems (resale, for instance).
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