Every water heater has multiple valves that control the flow of water, ease maintenance, and provide safety benefits. Leaks from these valves can be costly and they indicate an issue with the appliance.
There are several types of valves on your water heater. The inlet valve is located on the side of the heater tank, usually near the bottom so that cold water flows in and helps push the hot water upward. The hot water outlet valve is either on the side of the tank near the top, or it is located on top of the tank. There is also a pressure relief valve on or near the top. Its purpose is to release water and pressure safely in the event the tank overheats.
The drain valve is located near or on the bottom of the hot water tank. The sole purpose of this valve is to drain out the contents in the tank for routine maintenance or repairs. Otherwise, it shouldn't have water flowing into or out of it.
Valves can fail due to age, hard water mineralization, or pressure issues. Over time, the gaskets that seal the valves can crack or begin to weaken. Water may then begin to seep out around the valve. Sometimes, such as with the water inlet line, the issue is that a washer in the valve tap has worn out so the tap can no longer close the valve completely.
Hard water buildup can also put stress on the valves. If mineralization coats the valve tap, it may no longer move well enough to open and close properly. Mineralization inside the valve and valve lines also puts stress on the joints, which can lead to a leak. Further, as mineralization builds up in the tank, the chances of overheating and leaking from the pressure relief valve increases.
High pressure mainly affects the pressure relief valve, although it can also put some stress on the outlet valve. High pressure is a result of overheating in the tank, which can be caused by mineral buildup, a malfunctioning thermostat, or issues with a heating element.
Repair needs depend on the valve in question and the root cause of the problem, but the good news is most valve issues can be repaired. Older or damaged valves will simply need to be replaced, or the washer in the valve tap will need to be replaced.
Hard water buildup, especially that which leads to pressure relief valve leaks, requires flushing of the tank and cleaning of all the valve inlets and outlets. Other issues with overheating, such as a malfunctioning thermostat, will require troubleshooting and either repair or replacement of the malfunctioning component.
Contact a repair service if you need more information about water heater repair.