Electrical connection in tankless water heater - InspectionNews

JB Thompson · #1 (**permalink**) 08-12-2008, 02:46 PM

Hello friends,

I've inspected tankless water heaters in the last couple of years and without fail, everyone used a cord and plug rigged up in the bottom of the unit. I can't remember if all that I've inspected have been in the city (inspected) or in the country (not inspected). Picture included.

I normally write up that the electrical box should be secured, but have never liked it in there in the first place. Today's epiphany said, "maybe the darn thing shouldn't be there at all." Why I haven't thought of this before, I just don't know.

I looked up Rinnai's installation instructions online and the only thing they have is an outdoor rated disconnect switch which looks like it is outside the unit http://faucetclick.com/tankless-heat...32FFUC-INS.pdf (page 42)

So, what are y'all seeing out there in your real world. I'd be glad to hear what others are finding.

Thanks
Bruce

Dom D'Agostino · #2 (**permalink**) 08-12-2008, 03:38 PM

I usually see a better installation, similar to the one in the photo. (This house had 1 tankless for each bath, plus the kitchen.)

Dom.

Joshua Hardesty · #3 (**permalink**) 08-12-2008, 05:06 PM

Quote:

Originally Posted by Dom D'Agostino

I usually see a better installation, similar to the one in the photo. (This house had 1 tankless for each bath, plus the kitchen.)

Dom.

That is the dumbest thing I have ever seen!!! Well, not the dumbest. I wonder how long it will take them to see any savings after the initial cost of SIX of those suckers. I guess if I had the money...

I'd probably install two high-efficiency water heaters and a recirculation pump.

Oh yeah, back to the topic: I've never seen a tankless wired like that. How's that any different than a regular electric water heater being wired with a plug such as that?

Eric Shuman · #4 (**permalink**) 08-12-2008, 05:22 PM

JB,

Around here I usually see them hardwired with liquid tight conduit (the vast majority I have seen are installed outdoors) with an in-sight weather rated disconnect box.
See conduit snaking off at the right in the photo below. (Sorry not the best photo but what I had handy)

The instruction for Rennai that you posted specifically stated that it must have an on/off switch which a cord and receptacle is not. It also said the disconnect switch should be suitable for outdoor use.

I would say that installation is incorrect according to the manu. specs (if it is a Rennai).

Eric

JB Thompson · #5 (**permalink**) 08-12-2008, 05:27 PM

Quote:

Originally Posted by Joshua Hardesty

That is the dumbest thing I have ever seen!!! Well, not the dumbest. I wonder how long it will take them to see any savings after the initial cost of SIX of those suckers. I guess if I had the money...

I'd probably install two high-efficiency water heaters and a recirculation pump.

Oh yeah, back to the topic: I've never seen a tankless wired like that. How's that any different than a regular electric water heater being wired with a plug such as that?

Cord/plugs aren't usually inside an outer shell. (I think we've had the cord/plug on water heaters discussion before.)

Regardless, this is what the builder said, "that's not an issue. if it leaks, it'll just trip the breaker." Gotta love it. Bless his heart.

Ted Menelly · #6 (**permalink**) 08-12-2008, 05:45 PM

All the new homes I see them in around here have a mounted receptacle box inside and the unit plugged into it. I have called them all out for no GFCI and they always correct it.

Metal cabinet, water, exterior all falls into play. The inspectors pass them. I write them up and the electrician changes them out (well builder then electrician)

Yeah the breaker will trip if the water leaks on it. Yeah and you might be dead by then if you grab the cabinet before the breaker trips.

Jerry Peck · #7 (**permalink**) 08-12-2008, 07:02 PM

Bruce,

Is that unit installed inside the house or outside?

I ask because it looks to be 'outside' (just a gut feeling with nothing in the photo to relate it to) and the installation instructions state: (underlining is mine)
"4) This unit is designed to be installed indoors using the proper vent piping to exhaust by-products of combustion to the outside environment. Contact your dealer or Rinnai for proper vent kits. DO NOT operate this unit without vent piping connected. Exhaust gasses must be expelled outside the home. All pipe joints shall be taped to help prevent leakage around joints. (Aluminum tape is recommended.)"

It also says: (underlining is mine)
"7) The appliance should be located in an area where leakage of the unit or connections will not result in damage to the area adjacent to the appliance or to lower floors of the structure. When such locations cannot be avoided, it is recommended that a suitable drain pan, adequately drained, be installed under the appliance."

I see many other references to "Indoor Unit" and none to "outdoor unit".

The electrical connection is shown as: circuit goes to a disconnect which goes to the water heater and is wired (permanently wired) to the water heater inside the water heater.

*No cord and plug.* *No receptacle.*

JB Thompson · #8 (**permalink**) 08-12-2008, 07:36 PM

Quote:

Originally Posted by Jerry Peck

Bruce,

Is that unit installed inside the house or outside?

I ask because it looks to be 'outside' (just a gut feeling with nothing in the photo to relate it to) and the installation instructions state: (underlining is mine)
"4) This unit is designed to be installed indoors using the proper vent piping to exhaust by-products of combustion to the outside environment. Contact your dealer or Rinnai for proper vent kits. DO NOT operate this unit without vent piping connected. Exhaust gasses must be expelled outside the home. All pipe joints shall be taped to help prevent leakage around joints. (Aluminum tape is recommended.)"

It also says: (underlining is mine)
"7) The appliance should be located in an area where leakage of the unit or connections will not result in damage to the area adjacent to the appliance or to lower floors of the structure. When such locations cannot be avoided, it is recommended that a suitable drain pan, adequately drained, be installed under the appliance."

I see many other references to "Indoor Unit" and none to "outdoor unit".

The electrical connection is shown as: circuit goes to a disconnect which goes to the water heater and is wired (permanently wired) to the water heater inside the water heater.

*No cord and plug.* *No receptacle.*

You're correct. I grabbed the wrong installation instructions. The unit I inspected was an outdoor unit.

I'll begin looking for the correct instructions. Though, I doubt it will change the fact about the electrical connections.

Jerry Peck · #9 (**permalink**) 08-12-2008, 07:42 PM

Quote:

Originally Posted by JB Thompson

The unit I inspected was an outdoor unit.

Though, I doubt it will change the fact about the electrical connections.

http://www.foreverhotwater.com/documents/1110115.pdf

No change in the electrical connections. See page 19.

JB Thompson · #10 (**permalink**) 08-12-2008, 07:43 PM

I just pulled up the proper installation manual. The electrical connection section is identical to the link I posted earlier.

Good eye Jerry.

Thanks,
Bruce

JB Thompson · #11 (**permalink**) 08-12-2008, 07:44 PM

ooops. looks like you were quicker than I. we found the same link.