Insulating hot water pipe
 

I'm looking to insulate the hot water pipe that comes out of our hot water heater to where it goes into the wall. About 6'-7' total, 3' of it being copper and the rest being blue PEX.

With our natural gas heater, I've been seeing a lot of conflicting information on how much insulation and what type you can use. One site will suggest fiberglass tape from where the pipe comes out of the top of the water heater, while another will say you have to go 6" up before you can wrap insulation for fear of the flue being blocked and burning the house down.

What's the highest r-value insulating material I can use to insulate the hot water pipe exiting my natural gas heater without burning the house down?

Just get one of those pipe jackets at Home Depot. Anything more is well into diminishing returns.

Fear of the flue being blocked? What kind of insulation are you wrapping around that pipe? LOL

But yea, just get the stuff Mike said. Don't go too expensive.

In truth, you're not going to save that much heat wrapping them up, especially if you live in a 2 story house because you can only do the basement. I've wrapped them in my old bungalow as well as my new 2 story and it does help a little, but if you stop using the hot water for more then a half an hour it's going to cool off whether it's wrapped or not.

Its holds heat in the water for much longer compaired to unwrapped.

The best material to use would be rubitex. It's the black insulation that's on HVAC suction lines. The minimum thickness now is .75" but I like to use the 1" or thicker(though allot of outfits are still putting .5 on their linesets). An HVAC supply store will sell you just one stick. It will take allot more heat than the regular open cell hard foam plumbing insulation and it's flexible. It is however more expensive.

When I had my natural gas tank water heater I insulated it nearly everywhere I could. I also did the lines. You can check out my post here for more info:

http://ecorenovator.org/forum/conser...ter-pipes.html