Why not just flip the breaker switch? Or put the outlet on a switch? All of my outlets in bedrooms and living room have the top outlet wired to a wall switch.

If one twists the strands in the correct direction, and curves the conductor group in the proper direction, then standard fixture screws should tighten down without losing contact with any strands. There should be numerous visual examples of proper technique on the Internet.

I prefer to use crimped on ferrules sized for the wire gauge. One can also use crimp connectors to add a length of solid copper conductor. Note that proper sized ratcheting crimp tools are needed for these approaches.

Push holes for conductor connection are for solid wire only.

I think with the hard wired approach that the cord has to be rated for the circuit breaker current rating.

In any case, I recommend just pulling the plug. This will remove the device from the house circuitry and avoid any damage from line transients that might occur.

"Can I cut the plug-in cord from the water heater and run it through a 15 amp light switch in a box just inside the cabinet door?... "I've never connected stranded cord wire to a regular switch."

No, page 8 "Electrical Connection" of the instructions describe how the 2-1/2" water heater is to be direct wired if you don't want to plug the cord provided with the water heater into an outlet.

Yup ,switch the outlet ,not the heater. And why settle for 15 amp switch when a 20 amp is available. I'm not a fan of plugging or unplugging while plug is under load. Switch contacts self clean, receptacles and plugs don't.

True. I had assumed that the unit wasn't running, but that would depend on details of its design.

Take my word for it, after heater is without power longer than 1 day it will be "running" next time power is applied. It's a toss up when unplugging.

If you only have room for a one-gang device, install a combination switch-outlet and plug the water heater into the device.

@HU-16168550092: "And don’t forget that you have a homeowners policy or a property insurance policy that could be entirely voided if you begin to “custom wire” anything in your home."

So if he follows the manufacturer's instructions to properly direct-wire the water heater, his insurance policy could be "entirely voided"? Will my insurance policy be "entirely voided" because I added a switch and outlet to my remodeled kitchen? How about when I direct-wired my garbage disposal or dishwasher? Please provide proof of this assertion.

If the municipality requires an electrical permit and relevant inspections whenever new cable is run (as opposed to, say, just replacing a switch), and a fire is determined to be caused by faulty homeowner wiring that wasn't inspected, then the insurance company might have an out. One would have to read all of his policy's fine print to see whether that is addressed.

Thank you for all of the comments. Basically, what I want to do is put an on/off switch on the power cord of the water heater (essentially like you'd find on a floor lamp, but for 12 amps). Obviously, making the outlet a switched outlet would be the ideal, but the outlet is under a sink, under granite and under a window. I just don't see anyway to snake a switch leg up in an exterior wall (insulation) or laterally (water supply, drain, studs) to a switch. Using the breaker is a great idea, but my dishwasher is on the same circuit and my bride likes to start the last load just before we leave.

"Using the breaker is a great idea, but my dishwasher is on the same circuit and my bride likes to start the last load just before we leave."

The water heater and dishwasher cannot share a circuit. Each must have its own dedicated circuit. Even the basic Bosch SHE3AEM5N dishwasher uses 12 amps as does the proposed water heater.

It is not called a light switch on a lamp cord, but an electrical toggle switch. If you go the DIY route, make sure the switch is UL listed.

Ideally, we would want to know if there is a basement. A slab would indeed make circuit changes more difficult. How does power get to that location from the breaker box? Continuous conduit perhaps?

OK, how about this, which might make you more "legal" but doesn't require more conductors. Get a two-pole double-throw switch that fits in a surface mounted electrical box or use the existing box. Wire the power feed to the center, the dishwasher to one end and the heater to the other. (Dishwasher won't get heated water except for that which is already available.) If the dishwasher also uses a plug, then the switch and receptacle should be in a common box or one which has another box joined to it. Leave in dishwasher mode when you leave, otherwise keep on heater mode except when running the dishwasher.

Else, plan on a wiring exercise.

By the way, it is worth noting that you are very trusting. I wouldn't leave a dishwasher pressurized for an extended period without supervision because there is some tiny probability of a leak resulting in a damaged floor.

Why are you going through all this when you could simply unplug it (if turning off the breaker doesn't work for some reason). I have your exact set up with a 1.5 gallon heater for my bathroom sink. It has its own breaker.

@kaseki: "Dishwasher won't get heated water except for that which is already available."

• "Water usage per cycle: 3.5 gal" -- Bosch SHE3AEM5N Specs
• "Be sure that your water heater set at 120° F" -- Bosch SHE3AEM5N Installation

Upon re-reading, a single pole double throw could be used; for some reason I though the issue was 240 Vac related.

In any case, I would thoroughly investigate ways to wire the cabinet correctly with two circuits.