Thermal Blanket on Gas heater

[jbt]

I just installed a new Kenmore 50 GAL Gas water heater which is in the garage. Is it a good idea to wrap it with a thermal blanket? I've heard not to with the newer heaters.

 

[Master Plumber Mark]

its ok

they claim it is not necessary but it still is a good idea...

it is supposed to save you %25 on the
cost of heating the watger per year

just dont cover the new air intake on that unit

or you will regret it...

 

[Sponsor]

 

[hj]

blanket

SOme heaters are labeled with a recommendation not to use a blanket. But since most of your heat loss is up the center flue of the heater, which the blanket will do nothing to stop it, the blanket's usefullness is probably about zero.

 

[Jimbo]

First, many of the FVIR units have air inlets on the sides. You definitely cannot block these. Also, you cannot put any insulation on the top, as this would interfere with the draft hood. Most tanks today are well insulated, so unless it is an extremely cold garage, it is probably a waste of money.

 

[Dunbar Plumbing]

Sears brand Kenmore water heaters come with two sections of pipe insulation, a small piece that covers the exposed T&P valve and on electric water heaters the access cover for the wiring connections has a small round piece of insulation to put back over the wires, along with a more efficient setup for covering the upper/lower thermostats. They use styrofoam inserts combined with insulation. All water heaters have R-Values; meaning:


Insulation R Value
A measure of the insulating value of the insulation material. The higher the R value, the greater the resistance to heat transfer.


That statement says it all. If you can put your hand on the outside of a water heater and feel warm to the touch, that is thermal loss. You cannot use the two sections of pipe insulation on the gas water heaters because of a fire hazard, electric you can. Just imagine those thermos bottles you use for your coffee or drinks; the good ones will keep your coffee steaming hot for over 24 hours, the cheaper ones might keep it hot for most of a 8 hour day. Same theory applies with water heaters and how they are constructed to retain ready to use hot water.

 

[Master Plumber Mark]

thermal blankets

if they did not have some usefulness,
they probably wouldent sell them

if they only cost 12 bucks and are installed correctly,
according to the government (lol) it will save about
25% of your water heating bill.

-----------------------------------------------------------------
Heres a historical fun fact

a long time ago during the early 80s, A>O>SMITH water heaters
tried to make a better water heater by makeing one called a
"sub-chamber" style unit... it cost a lot more to make one...

they were pretty good units and their are still lots
of them out there, but they found out they could save
the same amount of energy by just wrapping a normal
water heater with a 10 dollar heater blanket.and simply modifying
the baffle assembly going up the flu pipe......

so basically the sub-chamber was shit-canned

So 20 years ago water heater blankets did save money.....
and they probably do today too.
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So do whatever makes you feel like you are saveing money
especially in a cold garage.

 

[alhurley]

if they did not have some usefulness,
they probably wouldent sell them....

aw, c'mon, Mark - you didn't really say that, did you?????

-art-

 

[Plumber1]

blanket

It's called marketing..............I never thought much of them.........

 

[Master Plumber Mark]

dont you trust your UNCLE SAM anymore???

well, do what ever you want ,,

but if they saved 25 % heating costs back in the 80s

I would say its a safe bet they are going to save

something similar in the 00s too......



Try this experiment

if you are standing out in your garage on
a cold winter night only in your underwear,
you would be putting off a lot of heat.....
and your body would be burning more energy
trying to keep itself warm....

basically shivering your cahooneys off


just try standing out there for 5 minutes
and I think you will get the point..
you will most likely want to put on some clothes
to keep warm and hold the heat in..



NOW---
the water heater is basically doing about the same thing
and it is simply common sense that if you
throw a blanket on that heater you are going to
keep the heater from trying to heat the garage..

also if it is in the house, during the summer time when
you are trying to COOL OFF the house,,, their is a phase
change or battle going on with the heater too....

the AC is trying to cool down the heater and the heater
is trying to heat up the space is is in ..

it is a very inefficinet way to heat the garage or house
through the hot water heater...

so spend 15 bucks and you will get it double back in
less than a year.....

 

[Dubldare]

My own professional recommendation would be to insulate the water lines only, being careful to keep clearance from the draft hood and flue pipe.

If you read the fine print in just about any manual that comes with water heaters, you'll most likely find that blankets are not recommended and can void your warranty. Additionally, as was stated before, the air intakes are not to be covered.

Alot has happened under the skin of water heaters since the mid-80's. The upper 1/3 of just about every heater is high-density foam insualtion, as well as the jacket being oversized to allow for more insulation.

To compare a current water heater to one from 20+ years ago is really quite a stretch.