Water leaking to the outside from relief valve on 7 year old water heater. Estimate includes replacing t&p relief valve and failed thermal expansion tank. We attempted repair at t&p valve but repair would not hold due to bad adapter built in to water heater. It appears that relief valve may have leaked for too long causing a corrosion issue. We called Rheem and got approval for a warranty swap. We took the old heater to Home Depot which was the place of purchase. We Replaced the water heater with a new unit provided by Home Depot under warranty. We replaced the Kohler shower cartridge in the downstairs shower. The valve is set too far in the wall so we had to recalling it using a a lot of caulk which was how it was previously installed.