A water heater drain valve drains the water contained inside the unit. Repair or replacement of the water heater requires drainage of the water prior to beginning work.
Water heater drain valves clog during the draining process when calcium, lime or iron particles are present in the water supply. These particles cause sediment buildup inside the water heater. The drain valve clogs when these particles dislodge, inhibiting or completely blocking the flow of water through the valve. Consistent leaking at or around the valve requires replacement of it to repair the leak. Replacement drain valves are made of plastic or brass. Brass provides more durability to the part.