Ok so you want to replace your water heater relief valve.
First things first, this can be very dangerous and I strongly recommend that you have it done by a professional.
Did you read the four reasons a relief valve leaks?
First turn the power off if electric or the gas off if gas.
Then turn off the water, it may be best to turn the main water valve off, many times the valves by the water heater don't hold and sometimes water feeds back through faucets in the home.
Drain some of the water out of the water heater, just below the relief valve. If you use the drain at the bottom of the water heater you may find that it will continue to leak after you try to turn it back off.
(another reason to have it done by a pro.)
With the power or gas off and the water off and drained below the relief valve, remove the drain pipe from the relief valve, if it does not have a drain pipe on it be sure to install one on the new relief valve. it needs to be the same size as the outlet of the relief valve and co to about 6 inches from the floor, without any possible way of installing any kind of plug or cap on it.
Once you have removed the drain pipe from the outlet
of the relief valve, check to be sure the water level is
below the relief valve and that no water pressure has
built up in the water heater.
Website by: Thomas Petito Reardon