Hot Water heater Home › Forums › Public Forums › General Plumbing › Hot Water heater This topic has 1 reply, 2 voices, and was last updated 23 years, 11 months ago by SylvanLMP. Viewing 1 reply thread Author Posts 16 Jan 2001 at 1:31 am #274419 MasterPlumbersKeymaster I have a State Model 510E hot water heater equipped with a therm-x-trol expansion tank. Recently it has been leaking water through the pressure relief valve. 16 Jan 2001 at 2:07 am #289722 SylvanLMPParticipant So you have one of the following 1- Defective T&P Valve 2- flooded or ruptured diaphram in your expanson tank 3- Water temperature set too high 4- Excessive water pressure Have a great one Author Posts Viewing 1 reply thread You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In