How high would you like your water heater sir?

[Gene South]

Though it may not look like it, the bottom of this tankless water heater panel is nearly 6 feet off the ground.

32110

[Jerry Peck]

Is it just my vision going of are those bricks not laid up with half-brick running bond pattern?

More like a quarter-brick running bond pattern, if that.

Sure looks weird.

[Garry Sorrells]

Looks like a 10" brick (2x4x10) and the resulting pattern from the corner.

[Gene South]

Looks like a 10" brick (2x4x10) and the resulting pattern from the corner.

This builder has used this pattern in many houses in the neighborhood. Here's a photo of another house nearby.
32115

- - - Updated - - -


Looks like a 10" brick (2x4x10) and the resulting pattern from the corner.

This builder has used this pattern in many houses in the neighborhood. Here's a photo of another house nearby.
32115

- - - Updated - - -


This builder has used this pattern in many houses in the neighborhood. Here's a photo of another house nearby.
32115

- - - Updated - - -



This builder has used this pattern in many houses in the neighborhood. Here's a photo of another house nearby.
32115


But back to the original subject. Is there a rule on how high a water heater can be mounted in this type of application?

[Jerry Peck]

This builder has used this pattern in many houses in the neighborhood.

But back to the original subject. Is there a rule on how high a water heater can be mounted in this type of application?

I doubt that it meets the intent of this:
- From the 2012 IRC
- - M1305.1 Appliance access for inspection service, repair and replacement. - - - Appliances shall be accessible for inspection, service, repair and replacement without removing permanent construction, other appliances, or any other piping or ducts not connected to the appliance being inspected, serviced, repaired or replaced. A level working space at least 30 inches deep and 30 inches wide (762 mm by 762 mm) shall be provided in front of the control side to service an appliance. Installation of room heaters shall be permitted with at least an 18-inch (457 mm) working space. A platform shall not be required for room heaters.

First, I don't see the level working space, second, if there was a level working space, I suspect the intent of the code is that one can stand on the level working space "for inspection, service, repair and replacement". There is an exception for air handlers in an attic where the unit is allowed to be located at the edge of the attic opening and worked on from there - but that is not an air handler.

[Raymond Wand]

How's that baby vented?

[Jim Robinson]

Probably electric.

[Jim Luttrall]

How's that baby vented?

It vents through the door, the silver/chrome slot near the top.

- - - Updated - - -


Probably electric.
Gas fired. Very common here.

[Jerry Peck]

What are the clearances to combustible material to the sides, top, bottom, and possibly to the back?

I usually see those mounted 'on' the wall, not 'in' the wall.

[Frank Adame]

A new home had the electric water heater installed in a utility closet where the top of the door was 6 inches from the top of the tank. I could barely fit my arm in that space so I could use my inspection mirror. There is no way any repairs will be possible without tearing up the top of the door. The conduit connector and grounding wire were left partially connected. This construction was given the building inspector's blessing.

[Jerry Peck]

This construction was given the building inspector's blessing.

How do you know that?

[Jim Luttrall]

What are the clearances to combustible material to the sides, top, bottom, and possibly to the back?

I usually see those mounted 'on' the wall, not 'in' the wall.
I can't tell the brand in Gene's photo but this is a typical install here (see stock photo)32129

There is a metal case installed between studs with the heater hung inside the case and air space all around. The case is manufacturer provided. All venting is done through the front door to the exterior.
My typical write up is the unsealed pipe penetrations at the base pan of the case. The case is sloped to drain to the exterior but the pipe penetrations compromise that integral drain pan.

[Jerry Peck]

I can't tell the brand in Gene's photo but this is a typical install here (see stock photo)32129


What is that brand?


My typical write up is the unsealed pipe penetrations at the base pan of the case. The case is sloped to drain to the exterior but the pipe penetrations compromise that integral drain pan.

Maybe the manufacturer does not permit penetrations through the bottom, maybe they was side or back penetrations - for that very issue you are writing up?

[Jim Luttrall]

What is that brand?



Maybe the manufacturer does not permit penetrations through the bottom, maybe they was side or back penetrations - for that very issue you are writing up?

Not sure of the brand, just a stock photo from the internet.

There is no other place for pipe entry.

[Jerry Peck]

If those are Rinnai tankless water heaters, I see some potential problems with those installation:
- Those look to be outdoor types, and ... are they still "outdoors" when installed in those cabinets? The manual I glanced through ( https://www.rinnai.us/documentation/downloads/U287-1932(00)_Outdoor_(2-17-2011).pdf ) said that they are not permitted to be installed indoors. To call that location "outdoors" would be debatable.

The side clearance to combustible material is 6 inches, and to noncombustible material 1/8 inch.

Being in a noncombustible metal cabinet which is between two combustible wood studs places the combustible material (the wood studs) within the 6 inches clearance from combustible material and would not be allowed.

Same for the clearance from the bottom and/or the top - which is 12 inches - any wood framing within that 12 inches would be a problem.

Also, that unit takes up the space where insulation is supposed to be, so unless the interior is bumped in, the insulation in that space does not meet that required for the thermal envelope of the wall (and further defines that as not being "outdoors").

Additionally, with insulation presumably installed above and below that unit ... that may not be permissible by the manufacturer either.

It would be quite interesting to see what that particular manufacturer says of installing their outdoor tankless water heaters in such a cabinet, and what the manufacturer of the cabinets say about the insulation issues, and what both say about clearances to combustible material, and (whatever else we can think of - but I see a lot of potential problems is the tankless water heater and the cabinet are not tested and listed together as a unit and what the combined installation requirements are).

Just some ponderables to be pondered.

- - - Updated - - -


Not sure of the brand, just a stock photo from the internet.

There is no other place for pipe entry.

When you inspect another of those common installations - check the manufacturer of the tankless water heater and the box, let us know, we can assist with the research. :)

[Gary Burnett]

Here is what they are installing at the exteriors around the Dallas area in new construction.
My pictures from the last couple of weeks on new construction.

[Jerry Peck]

Here is what they are installing at the exteriors around the Dallas area in new construction.
My pictures from the last couple of weeks on new construction.

How far are the combustible wood studs from the sides of the water heater?

How much insulation is missing (or is the wall inside bumped out toward the inside and insulated)?

how much insulation is above and below the enclosure?

[Bill Chinook]

I would imagine these units are on the garage side of the home and have bumped out section on the inside of the wall. I don't know of any place in texas that uses 2x8 studs for garage walls.

[Jim Luttrall]

Here is a Rheem unit installation instructions.
http://www.rheem.com/pdfs/_temp/AP14133RecessBox53.pdf

These are always a matched set with the door matching the venting discharge ports of the unit.
Very common and clean install. Usually set in a garage wall so missing wall insulation is not a factor.
The only problem I see with the installations is the item they list in the instructions about sealing around the pipe in the bottom. 99% of new construction installations here that use tankless go with this type setup.

[Jim Luttrall]

Thanks Jim! A great example why you need to know what is and is not allowed in your area. Clear concise difference between the US and CANADA.
May or may not be listed for use in Canada but this may have a bearing, From the instructions:

7. Install the water heater such that theair inlet and exhaust vent are aboveanticipated snow levels

3 or 4 feet of snow would block the air inlet in most installations. I figure many parts of Canada regularly get drifts that could easily reach these units. Also the pipes could freeze going to the units in very harsh winter climates.
They do have higher efficiency units though, that vent through the roof like interior mounted units.

[Jerry Peck]

Here is a Rheem unit installation instructions.
http://www.rheem.com/pdfs/_temp/AP14133RecessBox53.pdf

These are always a matched set with the door matching the venting discharge ports of the unit.
Very common and clean install. Usually set in a garage wall so missing wall insulation is not a factor.
The only problem I see with the installations is the item they list in the instructions about sealing around the pipe in the bottom. 99% of new construction installations here that use tankless go with this type setup.

Thanks - that answers some questions and raises some other things to look for:


Only these models of Outdoor Tankless Water Heaters will fit or function in this recess box;RTG-53X RUTG-53X
RMTG-53X PTG-53X
PH-20ROF



Recess Box Clearances - This recess box is designed to be installed with a Zero (0) clearance to combustibles. For service and proper operation, 24” (61 cm) of clearance is required in front of the recess box.



Plumbing and Piping - See Figure 5 for Pipe Locations. Follow all instructions in the Use and Care Manual for installation of gas and water lines. Holes are provided in the bottom of the recess box for all piping and wiring. These holes line up with the fittings on the bottom of the water heater.
1. Stub the water lines and gas pipe up through the bottom of the box (See Figure 5). It is recommended that shut off valves and unions be installed in the piping for future service requirements.
2. Connect the water lines and gas piping to the water heater in accordance with the instructions in the Use and Care Manual provided with the water heater.
3. Seal the holes around the piping with a silicone based sealant to prevent any water from leaking into the wall behind the recess box. Insulate pipes with foam insulation.

And Figure 7 on page 4 where it shows the drip ledge/lintel (which would require a through wall flashing) at the top.