leaky water heater relief valve Home › Forums › Public Forums › General Plumbing › leaky water heater relief valve This topic has 1 reply, 2 voices, and was last updated 23 years, 10 months ago by SylvanLMP. Viewing 1 reply thread Author Posts 16 Jan 2001 at 8:13 pm #274424 MasterPlumbersKeymaster Valve started leaking, dribbles, last nite. system is only 2 years old. the system is in a unheated garage with no “blanket” around the tank. Could a cold night cause the tank pressure to exceed the valve’s max pressure? 16 Jan 2001 at 8:39 pm #289727 SylvanLMPParticipant At night water main pressure NORMALLY increases do to less usage What could be happening is as the pressure increases the relief valve discharges slightly. You should contact a licensed Plumber to check this system and possibly install an expansion tank. If left unchecked over time this added thermo stress could weaken this tank enough to rupture. Have a good day. 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