Do water heater blankets do anything?
I'm installing a new gas water heater and one hvac/plumber who came down
said that they do help in heat retention and tank longevity. Is there any
thruth to this?
Personally whenever I've touched the outside of the water heater tank it has
never been warm so I can't see how a blanket would help in this respect.
well the blanket is insulation and if you tore open a modern water
heater you would find that the inside insulation is about 1/2 in thick..
so the blanket is about another 12 inch.. it just about doubles the
insulation value of the heater.. i put one on about 2 yrs. ago and never
had any problems with it.. it did seem to keep the laundry room a little
cooler... so it might just be working... what you go to loose?? about
$12 at home depot..
No, it does not. The temperature drops exponentially, not linearly; in
plain English, thinking of the insulation as being in the form of
(say) many 1/64" layers, the first such layer of insulation is doing
far more than the last layer. As others have said, it the outside
doesn't feel warm, insulating it isn't going to do much. Moreover, if
the water heater is in a warm room (such as a room with a furnace in
it as well), insulation is less worthwhile since the rate of heat loss
depends on the difference between the stored hot water temperature and
the temperature of the room. Now if the water heater is sitting
outdoors in the snow, more insulation may be worthwhile.
The outside is cool because it is losing heat so quickly that it stays
at nearly room temperature.
I insulated mine and repeated your experiment by sliding my hand between the
outside of the heater and the added insulation. It gets so hot in there
that you can't hold your hand on the metal. That's a reflection of the
heat that is escaping the uninsulated shell, and being trapped by the
I didn't fool with the "attractive" insulating blanket. I just wrapped
mine with leftover 3 1/2 inch batt.
Wrap it. Over the life of the heater, you will reclaim the cost of the
blanket, plus more. I personally have wrapped mine with the 1/4" double
reflective 3M product from ACE, plus a blanket. Do some serious taping, but
leave accessable any area you might have to get into in the future. Not
sure of the heating costs in your area, but in ours, the electricity and gas
have taken a big rate hike in just the last year.
Since water heaters last many years, the savings will pay for the initial
Be sure to check the warranty on your heater. Some manufacturer's void
it when a blanket is used.
I believe (I'm not sure) the concern is that the blanket can trap
moisture and can cause premature rusting, and therefore leaking, of the
I had a blanket on my old gas water heater. I had the heater replaced
in April and the plumber told me not to use a blanket on a gas heater
since it could get ignited. Any truth to this, if the blanket is
On Mon, 20 Oct 2003 14:44:34 +0000, David Combs wrote:
Why was that? I don't know. 25 years ago, when my family built our house
we used them on all the hot water pipes in the house. As a 12 year old
who wanted to help, that was one of the jobs that I was eligible for. Had
to rush the work on a few occasions, as the drywall didn't go up until the
pipe insulation was finished.
I wish the same had been done in the house we just inherited. Takes a
good minute of cold water until the hot water makes it to the bathroom.
In the winter with an under insulated basement, it only takes 15 minutes
to cool the water back down.
If you are debating doing it, my recommendation is to stop debating and
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.