Water heater not operating & City water issues

That dripping P/T Valve...

I'm told some folk test them periodically, and doing so keeps it from dripping.

I've found that they don't drip till somebody tests them.

So I don't test them, and when they drip, I don't expect that popping it open and letting it spring shut, will cure the dripping.

I go get a new one. They're inexpensive, the big box stores have them, and you don't need an "RV" part for an RV Water Heater. Just remove it, go match it up. Install the New One with Teflon Tape.