Wire size for electric water heater.

[razzorm]

I'm having an AO Smith heat pump water heater installed soon. Correct wire size is #8 or # 10 wire.
I already have a #6/3 wire that used to be hooked up to a hot tub that goes right by where the heater is going.
I can save myself several $$ by using this if it's ok. It will be connected to a 30 amp breaker.
Any comments?

Thanks

 

[brenndatomu]

#6 wire is larger than required, so you are fine...as long as the breaker size is matched to the new load, which I'd guess a 30A is correct

 

[semipro]

Agree with @brenndatomu and when I've done this I usually make a note in the breaker/fuse panel about the conductor size so that anyone doing future upgrades would know that they can install something with higher amperage requirements by simply changing the breaker/fuse. For example, you might be able to install a tankless (instant) water heater up to a certain size.

 

[Bad LP]

No problem using #6.
You don’t want to buying wire now anyway. Scrap was over 3/pound on Tuesday I was told.

 

[laynes69]

Yep, I bought a 25' roll of 10-2 for my heater and it was $50. Re-use what you have and save money!

 

[Highbeam]

Have fun attaching the #6 to the water heater’s #10 with a wire nut.

 

[Bad LP]

Have fun attaching the #6 to the water heater’s #10 with a wire nut.

Splice can.

 

[fbelec]

i must be thinking of a different name. what is a splice can? if you use a wire nut (blue color) keep a eye on it. going from 6 down to 12 in the water heater (because that is what they use in the tank) can act up like a bad splice and melt the wire nut. if the 6 is aluminum that is a no no code wise and will rot (dissimilar metal) if it is copper i would use a burndy style and if copper doesn't have to be split bolt type.

 

[brenndatomu]

must be thinking of a different name. what is a splice can?

Junction box

 

[Bad LP]

Junction box

Boxes in my world are standard wall type at the hardware store.
A splice can comes in many sizes and is a lot easier to work with using larger gauge wires. They come in plastic or steel.

 

[brenndatomu]

Boxes in my world are standard wall type at the hardware store.
A splice can comes in many sizes and is a lot easier to work with using larger gauge wires. They come in plastic or steel.

Pic, or link?

 

[gthomas785]

Put the splice in a junction box. If you're nervous about using wirenuts, you can use polaris taps but they are expensive.
"Big blue" wirenuts are commonly used for this type of connection and at 30A should not cause any problems. Get the ends of the wire aligned perfectly, then twist together, spin on the wirenut and keep twisting it until your arm falls off.

 

[Highbeam]

Boxes in my world are standard wall type at the hardware store.
A splice can comes in many sizes and is a lot easier to work with using larger gauge wires. They come in plastic or steel.

I don't know why, but they call those "gutter boxes" around here. All connections should be done in a box regardless. Should be plenty of room in a normal jbox. I hate opening up a wall to find wire nuts buried in the insulation.



It'll be like wrapping a piece of paracord (#12) around a tree trunk (#6).

 

[EbS-P]

Can you just run #6 into a disconnect then the required wire to the heater? Our code requires a disconnect.

 

[fbelec]

Can you just run #6 into a disconnect then the required wire to the heater? Our code requires a disconnect.

yes. that's it

 

[fbelec]

i've used 60 amp air conditioning outdoor disconnect for water heaters. much cheaper and serves the purpose well. 15 to 25 dollars verses 60 dollars and higher for a regular disconnect.