80 gallon water heater blanket

Can't you just wrap it with a big blanket or comforter?

I suppose I could make my own out of attic insulation, but that seems like a Bad Idea.(snip)

Actually, it sounds like a good idea. I did it myself and it works fine. Just have the kraft paper outside, and I use some slightly snug carpet thread all the way around as a backup to the duct tape.-Jitney

I went out an bought a 5 foot roll ~25 feet long of the silver foil stuff. Wrapped the water heater with that top down. Missing the bottom foot or so. Hot water rises anyway. Mine was electric so doing the top was a breeze. Becareful if your working with gas. I used the foil duct tape cause it sticks and stays.

Since water heaters are about the same size, how about two fortys? You'll have plenty of overlap. Seeing as how the capacity is proportional to the square of the radius, while the circumference is directly proportional to the radius.

Thanks to all for the ideas. Guess I'll see about making my own.

(I'm replying to myself, but I'm thanking all of you!)

Mike McSwell

Regarding energy savings for water heaters, a thought occurred to me. Isn't a lot more heat lost via convective air flow from the burner in the bottom up through the heater and out the chimney after the burner shuts off? I would think that heat loss would be a lot bigger than any heat loss coming out of the already insulated tank walls.

The water heater I'm dealing with is electric, so this is not an issue for me. I guess I should check the non-return valve in the inlet to the water heater, though, as I do notice the cold water at the tap can be quite warm...