asbestos

I got a water heater that turned out to be 110v the flex going to it has 2 blacks and a ground as you would expect. Can I just Disconnect one of the hots from the breaker, move it to the neutral buss (and flag it with white tape.) and use that setup as my 110v ?
It sounds fine to me but I have been told I don't know everything

to be clear I would have in the end
1 hot black
one black with some white tape going to the neutral
and a ground
in the box, a double pole breaker with only one pole hooked up

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Everyone is entitled to their own opinion, but not their own facts

kok328

Flag both ends and switch the two pole breaker to a single pole breaker and your all set.
When reusing the wire check the amp rating of the new water heater to make sure you have the correct wire and breaker size.
The higher the voltage, the lower the current so the old 240V wire may not be large enough for the new 120V heater.
I wish all questions came with the answer built in like yours.

asbestos

I knew there was something I forgot. wire size. I was going to flag on both ends, why switch out the breaker? other then so you don't have a double with one? is it just for general neatness and professionalism or is there another reason. it's about a 10' run to the heater which is 2200w. so I am hoping the wire is at least 12 or 10

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Everyone is entitled to their own opinion, but not their own facts

kok328

2200 Watt, 120 Volt heater.

What guage wire is existing?

What amp breaker is the 2-pole?

JoeD

It is against code to recolour a wire white.

asbestos

Did it. Yes technically if you re phase a wire it is supposed to be one gauge bigger or something. this was 10GA (double 20 breaker)wire running 1900 watts. flagged both ends. not perfect but good enough, and not worth tearing the walls apart to get to.
Thanks, All

__________________
Everyone is entitled to their own opinion, but not their own facts

kok328

10 AWG on a 30 Amp single pole breaker would be the correct setup. You'll find that a 20 amp breaker will run warm when heating the water.
2200 Watts / 120 Volts = 18.3 amps
80% of a 20 amp breaker is 16 amps
So using a 30 amp breaker would be appropriate.