I have a dishwasher and garbage disposal plugged into a 2-outlet wall receptacle under the sink. The GD is set up to a switch on the counter. Checking the fuse box, these both appear to be 20A. Kitchen was remodeled about 10 years ago.

I'm planning to install an Insinkerator Instant Hot water dispenser which draws 6.5A. With the DW drawing ~12A, seems like a simple issue to get an outlet adapter to allow for plugging in both the DW and instant hot. Max draw would be 18.5A. However, I can only find outlet adapters rated to 15A.

Question: Is it okay to have the DW (~12A) and IH (6.5A) plugged into an adapter rated 15A into an outlet rated 20A? Do I need to unplug the instant hot every time I run the dishwasher?

Thanks in advance for your input.

  • If you could get one, why not get a 20-A rated adapter? I think the 15-A adapter has enough of a safety factor that you don't need to unplug the instant hot when you run the DW, but personally I would get a 20-A rated adapter. Mar 28, 2018 at 18:47
  • I see that 2 ft long extension cords with 12 AWG conductor and a triple receptacle are commercially available. It is code to use an extension cord in a cabinet under the kitchen sink? Mar 28, 2018 at 18:56
  • Have not found an adapter that is rated 20A. They all seem to be 15A. A 20A adapter splitting the existing single outlet to allow for the DW and IH would solve the problem, if it exists.
    – Tony
    Mar 28, 2018 at 19:47

1 Answer 1


The best solution is to actually change the single gang box to a double gang box and install a second unswitched duplex outlet. This is not actually difficult for an experienced electrician, the DIY skill level is moderate. The total draw is only near max, if both dishwasher is on dry and hot water gets used, but insta-hots actually only run for a very short cycle if used. It shouldn’t trip if there’s nothing else on the circuit.

That said, I used this: https://www.homedepot.com/p/GE-6-Outlet-Grounded-In-Wall-Adapter-White-54947/203742151 or equivalent... specifically a model tho with a center screw, that’s critical for this application. If it’s the typical garbage disposal/dishwasher under sink plug that is a half switched duplex outlet, then the other two plugs on the switched row of the adapter are pretty useless. Regarding 15 vs 20 amp ratings, I think you won’t find 20 because it’s a NEMA 5-15 pin configuration.

(Footnote: I plan to change this when we remodel the kitchen and the cabinets are out to the 2-gang 2 duplex outlets described at the beginning, due to the location of the stud and the side they chose to nail the original to—mine was not the simple case of make a 1 gang into a 2 gang, mine actually has to change to the other side of the stud as well, I opted to use the adapter and have not had any problem.)

  • Thank you for the response! I've read elsewhere that using those 6-outlets isn;t a good idea given the GD is switched. Would this mean 2 of the 3 outlets either top or bottom would be useless? Also, the product description says "Combined load must be less than 15 amps or 1875 watts". Given that, I don't see an advantage over using a more standard adapter like this: homedepot.com/p/…
    – Tony
    Mar 28, 2018 at 20:27
  • The specific advantage is the center screw that’s ensures tight connection. Molded 3way adapters over time will typically begin to develop heat. Yes acknowledged the useless 2 outlets in my answer, it’s not likely that you’ll try and use them. Again the best answer is a 2-gang quad outlet.
    – Tyson
    Mar 28, 2018 at 20:33

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