Hot Water Heater Draft Cap and Vent

[Stanley Chow]

I was inspecting my first premanufactured double-wide home and found the gas-fired hot water heater in a concealed closet without ventilation. When the current owner removed the drywall panel, I found the draft hood replaced with a pipe clamp (see photo). Also found the lower pipe (female) was inserted around the upper pipe (male). Just want to make sure that there are no exceptions to the typical installation requirements for a premanufactured double-wide home. My common sense tells me that science is science regardless of the building type. A natural draft heater requires a draft - especially inside an unventilated closet. Your expertise and comments are appreciated.

[Dom D'Agostino]

Hopefully you have the make/Model/Serial Number? How about a photo of the vent or roof above the unit? Or the combustion/burner area?

The photo doesn't show much, but I suspect it's a Rheem. The only water pipe is on the Hot side, so it looks like a factory made Direct Vent unit.

Here is an example of a similar product, made for manufactured & mobile homes. (Not premanufactured, buy the way ;))

Rheem Gas Water Heater Mobile Homes (http://www.rheem.com/product.aspx?id=6652D01E-B5FD-4671-80A4-F06073A9DECA)

Dom.

[Ron Hasil]

A manufactured home water heater does have the flue pipe clamped direct to the water heater but also has a fresh air intake pipe at the bottom of the water heater as well. If they installed a standard water heater in the place of a manufactured home water heater it is wrong then. Here is a picture from the instruction manual.

[John Kogel]

Thanks, guys. That's 2 things I haven't seen before -
Direct vent with combustion air coming in thru the floor.
Support straps attached to the top of the tank with screws.

[James Duffin]

It looks like a bottom fed heater which is a manufactured home novelty also. I have never heard what makes a manufactured home need a bottom fed heater over a top fed heater.

[Stanley Chow]

Thanks guys for your responses. I learned alot today on manufactured home heaters. I got tripped up on the bottom FAI. Dom, the heater was exactly the same as the one you pointed out...a Rheem Warrior series. Ron, the illustration was very informative.

Next question....is it permissible to conceal the heater in a combustible enclosure? I think not. Gas valves and water valves are not accessible without removing a drywall panel and 10 screws.

[Jerry Peck]

manufactured home

Next question....is it permissible to conceal the heater in a combustible enclosure? I think not.

Stanley,

Keep in mind that the entire double wide is a "combustible enclosure" ... :)

[Stanley Chow]

Yes Jerry, except the double-wide is accessible through the doors. i was concerned about a flame inside a concealed (actually "sealed") enclosure without any means of access except by removing the drywall screws. Shut-off valves must also be accessible....right?

[Gunnar Alquist]

Stanley,

If you look at the labels pasted on the side of the tank, you will see wording to the effect "For installation in a manufactured or mobile home". On most water heaters, you will see "Not for installation in a manufactured or mobile home".

[Ron Hasil]

The units that are for manufactured homes have a sealed combustion chamber. Which is the reason why it has the make up air intake piped directly into the bottom of the water heater, and the exhaust pipe directly out the top.

I would say 99% of the manufactured homes I have seen, new and used, all had the water heater tucked away in a sealed closet space. Some have the access door inside while others have a removable access door outside.

I would recommend taking a class on inspecting manufactured homes for your area. The building codes codes for manufactured homes are no where the same as a standard building. Do not get me wrong lots of the basics are there, but there is stuff done and allowed in a manufactured home that would never be allowed in a standard building is my point. I have taken a code class that taught me about the manufactured home plumbing systems. Lets just say it was very enlightening.

As for shut off valves being accessible, as long as they have access to the main water shut off, it meets the requirements then. Half the manufactured homes I been in do not even have angle stops installed from the factory. So if you wanted to work on a faucet you had to go to the main water shut off. Like I said a different set of rules for these structures.