Does anyone know the thickness of insulation around your average water heater?

I have a friend who has a water heater in an attic which the attic door is too narrow for it to be removed.

I am wondering if it would be easier to remove outer shell and insulation and hopefully BFH it a little to get it smaller. Easier than reframing and installing a larger attic pull down stair.

I am consulting over the phone with a few picks to go by. The WH is 24" diameter the door opening is 21".

Thanks
Apparently the house was remodeled at some point and the attic access door size was reduced.

Are you talking about the foam insulation inside the tank?

Guessing he needs a new WH. Insolation will very. Years ago government reg. required more insulation then in the past. Thus many WH of the same capacity became a little larger.

If you could remove the outer skin it might work. I've never done that. Then inner tank isn't going to take well to a BFH.

I spent some time with a State rep a few months ago and to deal with a new regs and size issues they lowers the size of some WH by a few gallons to keep the external size the same with the needed new insolation.

How are you going to get a new one up there. A BFH on the old one might be ok but not on the new one.

What are the specs on the old WH? Does he want to go back with something of the same specs.

They do make them in all sorts of sizes. It's extremely unusual to have HWH in an attic. In fact I have never once seen it and I've been in thousands of customer's houses over the years, if not 10's of 1000's.

Recently HWHs when up in size for more insulation to be more 'green'. I have exactly the amount of space needed for mine. I bought a new one last year before they ran out of the old ones to avoid reframing walls and drywall. This may cause an issue with the install.

Standard trusses are 24" OC which leaves 22.5" stud bay to work with. Then you add 3/4" framing for pull down and you are at the 21" you have.

Not sure what advice I can provide if it has to be 24". If it were me and it had to be 24", then I'd go slightly off reservation. Go into attic find one of the bays they ended up at 24.5" or 25" OC. Then go near an interior wall, closer to center of the home. Cut a hole in the drywall. Then take a sazall and trim 3/4" off each truss. Get that bad boy up there. Sister up trusses, and patch hole.

PS I am not a plumber or carpenter, but I know how things are built.

Just cut it up with a sawzall and take it out in pieces. Easiest replacement would be a tankless, which would fit through the opening. Probably would have to upgrade electric, but pretty easy to run in an attic usually.

Thanks for the replies.

Looks like height issues preclude the use of a narrower new unit.

Apparently there is not enough gas flow for a tankless.

Down South it is not uncommon for them to be in the attic

quote:

Originally posted by Mikito:
Thanks for the replies.

Looks like height issues preclude the use of a narrower new unit.

Apparently there is not enough gas flow for a tankless.

Down South it is not uncommon for them to be in the attic

I'm in South Florida and we don't put them in the attic here either nor have I ever seen one there.

you could always install an electric tankless. Otherwise you're cutting a bigger hole and one of the trusses (rafter), since they're probably 24" on center and that's why your current opening is 21"

Ever watch Animal House? Think Dean Wormer's office. Brrrr!

You could install a tankless downstairs and have the water lines plumbed to it, if it creates a long run put a recirculating pump on it that will preheat the water at high use times

Is there room to move the old heater and abandon it in the attic? I have seen 2 or 3 in the same attic.

quote:

Originally posted by Skins2881:
It's extremely unusual to have HWH in an attic. In fact I have never once seen it and I've been in thousands of customer's houses over the years, if not 10's of 1000's.

A pretty common practice in warmer climates.

OP: Removing the outer shell and insulation will normally reduce the size by a couple inches. It does vary by the age/brand/model of the heater.

VERY common here to have a WH in the attic . I vote to drain and move it over out of the way.

I have heard of mounting a tankless on the outside of the house in the south where there is little chance of freezing.

It is probably 1" insulation. You can drill a hole thru the casing and "feel" the steel tank beneath. There will be welded tappings on the tank for the relief valve and maybe an unused side tap or two.

Empty, it does not weigh too much. He wants it out for the room?

Ear/eye/lung protection and a package of Sawzall blades will take care of the issue in about 30 minutes.

quote:

Originally posted by Woodman:
Empty, it does not weigh too much.

Depends on how long it's been in use and the hardness of the water.

I've had them be light enough to carry around and so heavy and full of sediment I've had to roll them out and use a bucket to load them into the truck.

I'd also vote to go tankless. Been very happy with mine.

quote:

Originally posted by rexles:
I have heard of mounting a tankless on the outside of the house in the south where there is little chance of freezing.

Yes, one of the luxury houses I manage has the tankless (gas) mounted right on the outside wall of the side of the house. It doesn't require any vent or anything. This is in South Florida.

VERY common here in Tennessee to see them in attics. Electrical code and space requirements however makes it less popular now than it used to be.

Simply take the access cover off the front and measure the thickness of the insulation and double that and subtract from the outer shell diameter for the internal tank size.

It might be possible to remove the stairway unit and gain 3 or 4 inches in width between the actual framing. Then just reinstall it when done. Around here the stairway often installed crossways of the joists, with them being headed off.

Yep, two in my attic. Removed one and decommissioned the other and left it as too difficult to remove.

Proud owner of two exterior mounted gas Rinnais now. Much happier not worrying about those attic mofos springing a leak.

quote:

Originally posted by jimmy123x:

Yes, one of the luxury houses I manage has the tankless (gas) mounted right on the outside wall of the side of the house. It doesn't require any vent or anything. This is in South Florida.

Please show me a manufacture's installation instructions which states their unit requires no venting materials if its mounted outside.

I'll be waiting...

quote:

Originally posted by Excam

Please show me a manufacture's installation instructions which states their unit requires no venting materials if its mounted outside.

I'll be waiting...

My Rennai tankless RU98 is an outdoor unit and requires no external venting to be used the unit have a vent slot built in to the front of the unit

The documents are here the specs show n/a on venting, the documents are downloadable

https://www.rinnai.us/water-he...98e-reu-kbp3237wd-us