How far away is your water heater from the electrical panel? If it is not insight or easy reach, you have to install a disconnect anyway, so consider that.

 

Like 5 feet away, it’s insight and not insight depends where your standing, if your standing on the left side of the water heater you can see both of them if your standing on the right side of the water you can only see the water heater

 

MC can come directly out of the wall. No need for the box. MC cable has the same protection requirement as NM cable. I doubt much damage is happening above the WH.

 

I just thought the mc cable looked better than nm since it was exposed, and a box looked better to me than just a hole

I can use a plastic box for that purpose though?

 

You want the cable to pass thru the box unbroken?

 

I got a plastic box with a large knock out, I’ve already pulled it through

 

I was bringing up the location of the panel just to make sure you could just use the MC. And you can, either with or without the box. The only thing I was getting at was the disconnect would be metal and you would need special MC adapters, but with none or a plastic box, you're good.

 

What type of cable is coming from the panel? MC all the way?

 

Yea all the way

 

Get a single gang pop-in low voltage box/ring, it is open in the back. Cut out the wall to fit the box. Get a metal single gang blank plate that has a knock out. Get a push in NM connector and insert into the knock out, then push the MC through the connector, you might have to bend the tabs in the connector some. Screw plate to box.

 

Just noticed you already had a box, you could drill a hole in it and use it. or get the low voltage box/ring.

 

A breaker lock allows a padlock to be installed to prevent turning the power on or off, for example while being worked on.

 

Thanks for clarification.