NEC 422.31 & undersink water heater

[groups]

Hoping someone with real experience installing these can help: we're about to install a CEC Powerstar tankless water heater in a lav cabinet under the sink. Unit requires a 240v 40a circuit which we're ready to run over to the lav.

The manual states: "When the Powerstream Pro is not within sight of the electrical circuit breakers, a circuit breaker lockout or additional local means of disconnection for all non-grounded conductors must be provided that is within sight of the appliance. (Ref NEC 422.31.)"

So, in the field, what do you guys generally do here? We don't really want to add another (possibly expensive) box of some sort under the cabinet; do you have to add some kind of lockable disconnect box at the panel? Our Instahot kitchen sink unit has no such disconnect but there it's a 120v wall-plug unit which I presume fills the bill.

Should we/could we instead simply add a 240v pigtail to this unit, and then install an appropriate wall receptacle and therefore fulfill this requirement?

tia

[RBM]

A plug and outlet serves as a disconnect. In this case, some means of locking the breaker in the off position, or locking the panel door will suffice, if you don't want a disconnect under the sink

[Edwin Pawlowski]

That works. Also makes for easier service if it has to be removed.

[RBM]

I think if you have room for a forty amp outlet and cord set, it would take less room to install a small two circuit, breaker panel

[Steve Barker]

You could use the pigtail and outlet, OR an a/c disconnect. They're only about $6

[trader4]

I'd put one of the simple pull type disconnect boxes near it, similar to the ones with fuses that are used on outside AC units, but without fuses.

[LayPerson Tom]

Cord and plug sounds like a nice disconnect. I suggest you contact your local code enforcement people, they are their to help you with questions.

tom @