Placing an electric HW tank in a blind corner

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kiwi_outdoors

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Our kitchen has one of those unavoidable blind corners where two rows of cabinets meet at right angles. To the left, is a cabinet with slide out drawers. To the right, is the sink cabinet, with an unused GFCI for a garbage guts that we will never install. My plan is to install a Rheem 2.5 gallon electric HW inside the blind corner, by instlaling an access door, weathertight, in the exterior wall. Core a few holes in the sink cabinet wall for power cord and water flex lines to/from fittings. Core two holes in the stucco for drain line (from drain pan) and pressure reilef line. This new tank serves only the sink, not the dishwasher.

This a sort-of a repeat of what I recently did for our bathrooms. It's so very convenient having essentially instant hot water on tap. Its simple and reliable. The reviews of the "instant" types of electric heaters did not sound like they were free of leak issues, so I chose not to use that tye of solution.

Note - the little 2.5 gallon Rheem tanksis a plug-in electrical connection, unlike its hard-wired big brothers.

Any comments?
 
We've used plenty of those 2.5 gal. types on utility sinks in garage or shop.
Main complaint is that they only provide less than 70% of rated capacity before mixing inside takes effect and the result is, of course, not-hot water, until the house's hot gets there. This can then cause the arrival of the main WH's hot to be mixed with the lukewarm tank and uneven temps (potentially).
As a plumber, we recommend recirculation loop primarily as the actual solution.
For a kitchen, even a non dedicated recirc, like the TacoGenie with pushbutton or motion sensor or Laing undersink units are not terrible. When these are used, the cold tap initially is often not cold but very warm (which is why we don't recommend using at bathroom sinks) but, for kitchens, not too bad. I have one set like this at my home and it is satisfactory.
 
breplum:
70% capacity is fine for us. Thanks for that nugget of info.
If it turns out to be a issue, I will feed it from the tankless HW heater instead of CW.
 
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I think it will work fine, but I wouldn't cut a hole in the outside wall, I would think you can do it all from under the sink.
 
RS said:
I think it will work fine, but I wouldn't cut a hole in the outside wall, I would think you can do it all from under the sink.
Click to expand...

Equipment of any kind needs to be readily accessible for inspection and maintenance. I will be using an RV Baggage compartment door in the outside wall - it includes a weather seal around the entire perimeter.
 
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kiwi_outdoors said:
Our kitchen has one of those unavoidable blind corners where two rows of cabinets meet at right angles.
Any comments?
Click to expand...

Yeah--who designed that kitchen? They make blind corner cabinets just for that purpose, in the event that the kitchen designer or homeowner doesn't want a "lazy Susan" style cabinet to prevent it in the first place. I inspect a lot of homes and every now and then I'm faced with observing some kitchen design challenges...

But sounds like modifying your cabinetry isn't in order, and yes you need to make that additional water heater accessible. Personally a hole in the house from the outside sounds pretty extreme but if that's the way you need to do it to allow access, so be it. A nicely installed RV door as you suggest sounds like a well done plan. Make sure it has a lock on it, and don't lose the key.
 
re losing the key:

its an RV baggage door - all keys are the same !! (i.e., not really a lock, more of a latch, since anyone can get a key)
 
well, its done. I just managed to clear the cabinet wall on the left and a wall stud on the right. For now, the relief pipe is PVC (not to code) - but it was so much easier than doing it in copper (I can change it later). There is a seismic anchor (wood and blue strap). The drain pan is a 14" X 3" round cake pan. I set the thermostat to 166 deg F - its great to have quick hot water. For the time being, its fed from the gas tankless main HW unit (it was a simpler project to do that). The door way is 10" clear - I was just and only able to get my torso inside that door opening - which made the project easier.
 

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Looks good but there are a couple problems if one wanted to get picky.

Glad you completed your project ✌️
 
The cake pan is a great idea. Looks a bit more robust than some of the overflow pans I've seen! Consider adding a small water alarm to it, so that if the bottom gets wet you'll hear about it, literally...
 
Drain pan is too deep, should be no more than 2” deep for that heater.

Warning labels covered with strap,

Strap bent the outside of the shell.

Straps must be removed to service.

I don’t see a stop valve, it may be there though.

You pointed out the relief Is improper materials.

Some places they want cpvc for the pan drain piping, not pvc.

You asked for it 🤣🤓🤷
 
Thaks for the feedback :)

Drain pan is too deep, should be no more than 2” deep for that heater. Why 2" deep? (just asking). I never found any shallower specific drain pans on line that seemed right for this little water heater.

Warning labels covered with strap, Yup, thats true.

Strap bent the outside of the shell. Nope - it arrived that way from Home Depot's shipper.

Straps must be removed to service. Of course - this thing is so tiny thattrying to anchor it for seismic is a problem.

I don’t see a stop valve, it may be there though. The stop valve is under the kitchen sink, at the supply point.

You pointed out the relief Is improper materials. Yup - I learn't this when I sold our house in 2007.

Some places they want cpvc for the pan drain piping, not pvc. Well, thats good to know.

Consider adding a small water alarm to it, so that if the bottom gets wet you'll hear about it. Why - it drains to the outside thru a 3/4" PVC pipe , onto a walkway beside our house that we use daily.
 
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The water cut off should be located in the room with the water heater.

The instructions say 2” max, I guess that’s all the water they want it sitting in until you find it or it overflows.
 
BTW - ths philosophy for the mini heater is
  1. The space under the sink is fully occupied by slide out bins for garbage and recycling. So its not going there.
  2. To make use of available space in the blind corner - since we paid for that space, as it were.
  3. Get hot water to the faucet quicker and hotter than the tankless provided from its "closet" in the garage. We were tired of having to wait for hot water. Its a quality of life issue - and it saves water.
  4. Make a practical and safe installation, even if not code compliant.
  5. Be accessible for replacement when it eventually leaks or needs a new heating element.
  6. Must fit through the access door (it does, with 1/4" to spare)
BTW - this little heater is shipped with a 3-pin plug. Its plugged into a dedicated GFCI 15A circuit under the sink. (left over from when we took out the insinkerator during a kitchen remodel)
 
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