Plumbing pressure relief
I'm running on internal water (not city water). I don't leave the water heater turned on all the time (too wasteful to do so) and when I turn it on it raises the pressure in the whole plumbing system ...
Forum Discussion
Drain the water heater and refill it, that will re-establish the air pocket in the tank and allow for expansion. See your water heater owners manual for more information.
