# Water  Heater  Insulation



## globe trekker (Mar 1, 2013)

Greetings to you all!

I have a natural gas water heater, and I am considering purchasing some thermal

insulation to install on the exterior of it.

I have heard various opinions and statements regarding applying more insulation.

*For:* "Yes, it definitely helps to retain in the heat and the reduce the cycling of

the water being heated and reheated over and over."

*Against:* "No, more external insulation will not do anything to retain the heat in.

You're just wasting money on applying something."

Have any of you actually installed additional thermal insulation on your water

heaters, and have actual statistical data to support your position, ..one way or

the other? Maybe even some thermal imaging data?

Thanks for any relevant input !  



 



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.


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## Frank (Mar 1, 2013)

It will help reduce storage losses.  Make more difference on an old water heater than on a more modern one that has more insulation from the factory.


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## Alias (Mar 1, 2013)

As someone who has installed many a water heater blanket under DOE, DEO, & PG&E weatherization programs, I will say yes.  The only thing you need to look for is a label on the water heater that states NOT to install a water heater blanket.  This label is found on many newer water heaters.

Sue


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## globe trekker (Mar 1, 2013)

Thanks for the input so far!

Sue,

What's the deal with the sticker? Does it void any warranties on the WH itself?

If the blankets, or other types of externally applied, thermal insulating materials definitely

work, then I want to start reseaching for something that I can install cheaply.  

.


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## ICE (Mar 1, 2013)

I have been told (contractor) that FVIR water heaters should not be covered with insulation.  It has to do with combustion air.


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## Msradell (Mar 1, 2013)

I think if you look at the heater blankets, many of them the net to be used with gas-fired heaters. They are only recommended for electric water because the safety considerations.


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## Alias (Mar 2, 2013)

globe trekker said:
			
		

> Thanks for the input so far!Sue,
> 
> What's the deal with the sticker? Does it void any warranties on the WH itself?
> 
> ...


globe trekker,

Water heaters that have the sticker are insulated already.  It would void the warranty I believe.

Sue


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## Alias (Mar 2, 2013)

ICE said:
			
		

> I have been told (contractor) that FVIR water heaters should not be covered with insulation.  It has to do with combustion air.


ICE,

What is a FVIR water heater?  I've blanketed many a gas fired water heater.  The type of water heater blanket that globe trekker posted states it can be used on all types of water heaters.

Sue

Sue


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## mark handler (Mar 2, 2013)

See page 12

http://www.google.com/url?sa=t&rct=j&q=gas%20water%20heater%20external%20insulation&source=web&cd=3&sqi=2&ved=0CEUQFjAC&url=http%3A%2F%2Fwww.rheem.com%2Fdocuments%2Ffury-gas-canada-guardian-use-and-manual&ei=ghsyUYmjJqbRiwKfy4DoAw&usg=AFQjCNFK1Pf0XulF7K7OB8HoS0AFhSJG_g&sig2=PJZkBbVHRsvh6S3_6qs0fA&bvm=bv.43148975,d.cGE


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## ICE (Mar 2, 2013)

Sue,

FVIR is flammable vapor ignition resistant.  They are not required to be 18" above the floor in a garage.

http://www.ashireporter.org/HomeInspection/Articles/What-is-Different-About-FVIR-Water-Heaters-/99



> The most visible change in the new water heaters is in the way the combustion air gets to the burner. At first sight, the average person will likely see no difference in the FVIR models. Closer inspection reveals combustion air intake openings in the jacket at the sides or the base of the water heaters.


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## Sifu (Mar 5, 2013)

On a related note......We sometimes run across builders who install the water heater in the attic.  The practice has been to make them build a small (4'x4') insulated room around them with the idea that the thermal loss suffered by the tank will prevent them from freezing (as the code states they must be protected from freezing).  I disagreed with this but was unanimously vetoed.  To my thinking, making them do this, then making them add combustion air ducts since we made a confined space is not valid.  Building a room in an uninsulated space with insulated walls does't make it an conditioned space, and if there is enough thermal loss from that appliance there are probably bigger problems.  Add to that, I have not found one single manufacturer that recommends wrapping the tank, much less building an unconditioned confined space around it.  But what do I know?


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