We have a water heater and it leaks water though the relief valve. But, it only happens when the water heater is warm. If the temp is turned down (a.k.a. Off) the relief valve stops leaking. What's causing that ? Then someone volunteered that a few years ago a plumber was there and replaced the guts of that relief valve. Leak: Its a little more than a constant trickle, does not appear to an issue with the expansion tank or water hammer effect.
Any idea what is causing this behavior ? Thanks