Re: Splitting 220
You can if there's a neutral. Sometimes people will tie the neutral connection of the 120V outlet to the ground wire to make it work, but that's not considered safe.
Regardless, it's a violation of code to do what you've described. The water heater requires a dedicated circuit.
The proper way to split it out would be to install a subpanel in the circuit at the point you want to split. However, that subpanel would need to have separate ground and neutral going back to the main panel; ground and neutral may not be bonded in the subpanel.
The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.