Hot water heater rough-in wiring

[JoeNorm]

Is it safe to assume 10-2 will cover all water heaters? Do some of them require a neutral?

I have been roughing in with 10-3 because I haven't been sure but wondering if it is a total waste.

 

[ptonsparky]

10/2G
10/3 is a waste. I’ve never seen a neutral required.

 

[Eddie702]

Some water heater coming through with 5,5kw elements but 10/2 still covers that @240 volt.

Used to use 10/3 around here when they used the switch in the meter for peak/off peak.