I installed a brand new electric water heater today. The problem I’m have is that the t&p valve is leaking. Do to this leaking I changed it two times thinking it was defective. Still leaks. I replace the old 40 gal water heater with another 40 gal water heater. It starts leaking as soon as the tank fills up (water temp is still cold). Do you think an expansion tank would fix this problem? I thought that expansion tank work when the water gets hot? Could I have a bad pressure regulator? What are your thoughts?

Hi Russ and welcome, your regulator could be bad, what does the pressure gauge say? If you don't have a gauge, get a hose bib gauge and check it. Good luck

Thanks I will pickup a gauge today and let you know.