At boat this week end. Turned on water, hot water, etc. A couple hours later found water in bilge and condensation dripping from aft bilge area. Found hot water steaming from pressure valve. Couldn't stop valve from being partial open. I assumed valve was bad. Replaced it. Turned on water heater and everything seemed good. Would like to test hot water temp. Should I be concerned about the thermostat? Do valves go bad and open for no reason? Maybe the valve seal is bad? I couldn't tell. Has anyone had pressure build if tank is cold when turning on water heater and not using hot water? Per manufacturer of tank the set point of the thermostat is 170 degrees Fahrenheit. We did not use the hot water prior to the valve releasing. The water in the tank had to be less than 60 degrees Fahrenheit when it was turned on.

Any help would be appreciated. Boat is new to me, still learning.

Dan