Start with safety

Never cap, plug, clamp, or add a shutoff to the relief valve or its discharge pipe. Do not fit a higher-pressure valve to stop the drip. The valve must match the heater's requirements. Keep people away from the discharge outlet, where hot water can cause burns. Watts relief-valve safety guide.

If water is pouring out, steam is present, or the hot water has become unusually hot, stop using the heater and get urgent qualified help. Turn off its heat source only if you can follow the unit's shutdown instructions from a safe, dry place. Do not approach a wet electrical panel or open equipment covers. A large hot-water discharge can indicate overheating; it is not a reason to keep experimenting with the valve. A. O. Smith water-heater use and care guide, troubleshooting section.

Find where the water starts

“The relief valve is leaking” can describe several different things:

  • Water coming out of the discharge pipe: the valve may be opening, or may not be sealing fully.
  • Water around the threaded valve connection: the joint may be leaking.
  • Water at the tank fitting itself: the tank connection needs its own inspection.
  • Water nearby from another source: a supply connection, drain valve, or condensate line can make the relief valve look responsible.

A photo taken from a safe distance helps show the starting point. Do not touch the pipe to find out how hot it is. The repair should follow the actual leak location. A. O. Smith Bulletin 52.

Three checks that explain a recurring drip

1. Water pressure over time. A single normal reading does not show what happened overnight or while the heater reheated. A qualified person can check incoming pressure and record its highest level. If supply pressure is excessive, the pressure-control equipment needs attention. Replacing the relief valve does not correct incoming pressure. A. O. Smith pressure and expansion guidance.

2. Pressure during reheating. Water takes up more room as it warms. In a closed water system, a check valve or pressure regulator may prevent that extra volume from moving back toward the supply. Pressure then rises inside the home's system. This is called thermal expansion. A drip after a shower, while the heater reheats and no taps are running, is a useful clue. It is not a diagnosis by itself. A. O. Smith Bulletin 45.

An expansion tank gives that extra water a place to go. Its presence alone does not prove it works. The technician should check its size, condition, and air charge against the system's measured pressure and the manufacturer's instructions. An expansion tank and a pressure regulator have different jobs. One does not automatically replace the other. A. O. Smith pressure and expansion guidance.

3. Actual temperature and valve condition. The thermostat setting is not a measurement of the stored water. Ask the technician to check the actual water temperature, the controls, whether the replacement valve matches the heater, and whether debris or damage keeps it from closing fully. A newly installed valve can still need correction, but “new” does not rule out a system problem. A. O. Smith use and care guide, relief-valve troubleshooting.

What you can do before the visit

Leave the valve and discharge pipe alone. Record when the drip happens, whether it stops between heating cycles, and whether it began before or after the replacement. Keep the replacement receipt, heater model number, and any previous pressure readings handy. Move belongings away if that can be done safely without touching wet equipment.

Ask the person returning to explain what was checked the first time. A helpful question is: “Was the valve itself faulty, or was it releasing water because of pressure or temperature?” Recent work may have applicable coverage, but the receipt and terms decide who pays. A repeat leak alone does not establish free work or a defective heater.

What a resolved repair should include

We recommend finding out why the valve dripped and confirming that the repair addressed that cause. Ask for the leak location, pressure and temperature findings, work performed, and the result after a heating cycle. If the problem involves the home's supply regulator or other plumbing, confirm the qualified party responsible and whether that work is included in the quote. MGI water-heater service does not imply general plumbing service.

Replacing the whole heater is not the automatic answer. A sound tank with a correctable pressure or valve problem may have a repair path. A damaged tank or unsafe condition changes that recommendation. What matters is fixing the cause and confirming the result, so you can use hot water without wondering why the same drip returned.