My wife just bought an instant hot water unit for the kitchen sink and
I have a question about the wiring.
There is currently no outlet to plug the unit in under my sink
(Standard 3 prong plug) and the clearance is quite tight under there
for me to put an outlet, so can I do this:
On the other side of the wall is a receptical. Can I remove this outlet
drill a whole into the kitchen cabinet, and hardwire the unit directly
to this receptacle (Then replace the receptacle). I will have to cut
the end of the plug of the water unit of to do this and want to make
sure that this is not dangerous to do.
No. The cord of an appliance is not permitted to pass into a wall.
You need to have a receptacle (or a junction box if you wish to
hardwire the appliance) on the kitchen side.
It is very common to have power under the kitchen sink, for a garbage
disposal or dishwasher. Do you not have either of these appliances?
P.S. This suggests to me a related question: would it be NEC
compliant to have receptacles back to back through a wall, using a
single electrical box? This would require an electrical box with just
4 sides, of depth equal to the finish depth of the wall.
I have a gabage disposal but that is hardwire (No plug) to a switch on
my Kitchen counter. So because it's switched it'sno good for this.
Besides it not being code is there any danger to this? We are not
selling the house anytime soon and would just remove it when we do.
I believe it is OK for an appliance cord to pass through a hole in a
kitchen cabinet, just not a hole in drywall. The cord from the
hardwired dishwasher should enter a junction box. This would be a
good place to tap into for power for the instant water heater. Either
hardwire the water heater here, or install a duplex receptacle in the
junction box and put a plug on the dishwasher.
You need to check that the circuit serving the dishwasher has
sufficient capacity for the water heater as well. Determine whether
the existing circuit is dedicated to the dishwasher, and whether it is
15A or 20A. Then determine the current draw for the dishwasher and
for the water heater, and make sure the sum of the current draws is
less than the rating of the circuit.
I haven't done this particular work myself, so you might want to wait
for someone else to chime in with their ideas and confirmation that I
haven't said anything stupid.
P.S. Just because the garbage disposal is switched (as you noted in a
separate post) doesn't mean it is entirely out of the picture. For
example, it is possible that it and the dishwasher are on the same
circuit, and that they are fed via cable with 2 hots (one unswitched,
one switched). You should probably trace the garbage disposal circuit
as well, so that you know exactly what is going on electrically,
before you add another device.
How about Just running romex out of the box on the other side of the wall,
through the wall and install a box on the other side of the wall under the
sink. Run the romex into the new box, put an outlet in the new box and plug
the heater into it. Clearance may be tight to work in but that would be the
How about one of those brown surface mount duplex recepticals? That
would eliminate the need for a J-box. Wire it into a nearby outlet box
with some romex. (the problem will be probably too many conductors in
that outlet box you tap.)
Installing a new surface mount J box with receptacle under the sink as an
extension of the one on the other side of the wall is definately the
preferred method (as indicated by CR above). It still may not be to code
depending on the load requirements of the heating unit and what the plug on
the other side was used for but ignoring that, it should work best this way.
You can use a short length of conduit to cover the wire. Use a NonMetallic
box (blue box) and conduit and it will be easier because a metal one needs
ground bonding at both ends of the conduit and in the J box.
If you must hardwire the appliance to the old j-box. do not sinply connect
the stranded power cord wires to the screw terminals on the side of the old
receptacle, instead pigtail it with solid core wire and use a wire nut to
make the splice. The biggest safety concern is stranded wires becoming
uncaptive and causing shorts or being pushed out of the terminal while
tighning. These strands have a habit of popping out when you push the
assembly back into the j-box when you cannot easily inspect it.
1) Check to make sure that your not going to blow a breaker ever time this
thing turns on (what are you sharing power with?)
2) If you drill a hole in the back of the box use a rubber grommet to
protect the cord.
The unit is only 4.5 amps. If I do it the way of drilling to the back
of the receptacle, its sharing with some very lightly used receptacles
and some light fixtures, nothing major on it at all.
Thanks for the "GOOD" advise about the rubber grommet.
I don't think going to the same line as the dishwasher will be good.
DW is rated at 15amps, this unit at 4.5. Not sure if anything else is
on that line but it's cutting it close.
So without worrying about code can this be done, is it safe to cut the
power cord and run it directly to the back of the receptacle (B to B, W
to W, G to G all with wire caps and electrical tape). I'm worried
about safety only. Not looks as this will be hidden and not passing
inspection as when I sell the house I will simply remove it.
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