Pardon any misused vocabulary, I'm still kinda new to this stuff.

I have a dedicated 15 amp circuit wired to a 1 gang, 2 outlet receptacle under my kitchen sink that powers the disposal. The entire receptacle is switched.

I want to add an instant hot water heater to this sink. The disposal is rated at 10.2 amps, and the instant hot water heater is rated at 6.25 amps. 10.2 + 6.25 = 16.45, clearly above the 15 amp circuit rating.

Adding a new circuit or upgrading the existing one to 20 amps is more work than this is worth to me, so I was wondering if I could just break the tabs off the receptacle so that the top and bottom are no longer connected, and then wire the switch to switch between them, so that one is always hot. That way the hot water heater is on all the time, except when the disposal is needed (presumably for just a few seconds). This shouldn't ever exceed the circuit's amp rating, but it just sounds weird.

If it changes anything, I'd be willing to expand the box to 2 gangs and then switch between the 2 receptacles.

Is this a crazy idea? Is it against code? What problems could it cause that I'm not thinking of?

I found this question which asked a similar question, but the GFCI stuff seemed to complicate matters. It didn't seem like the idea of switching between outlets was the issue though.

  • 1
    I did the same thing, the receptacle was fed hot, S.P. switch was a switch loop, I was not able to fish new switch wires, so I used an RIB2401B on a Raco 187 j-box since existing receptacle was flush, existing S.P. switch controlled coil, wired the instahot to the N/C and Disposal to N/O, GFCI breaker Jan 5, 2022 at 5:11

1 Answer 1


Crazy but in a good way. Brilliant actually. Use any common 3-way switch, I don't see a problem with it.

The only issue that might call for a 2-gang switch box is the need for GFCI protection on both appliances. Simply use a GFCI deadfront prior to the switch. You can't use a GFCI receptacle because that would be adding a kitchen countertop receptacle, and those can't be 15A nor share with heaters or disposals.

If somebody made a combo GFCI-1 socket-switch where the switch was 3-way and the GFCI was deadfront, that would be perfect, but I would not get my hopes up.

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    or change the breaker to a GFCI breaker Jan 5, 2022 at 9:57

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