Water heater leaking? What to do right now

1. Make it safe and stop the water

A. O. Smith says to turn off the power or gas before inspecting a leak, then turn off the water supply. Rheem’s emergency advice is to close the valve above the water heater on the cold-water intake. If you cannot find or close it, shut off the main water valve to the house. Keep children and pets away – the water in the tank can be scalding hot.

2. Find where the water is coming from

• The top: loose connections on the hot or cold pipes, or the relief valve.
• The relief valve or its pipe: see below.
• The drain valve near the bottom: may just need tightening or replacing.
• The bottom of the tank itself: A. O. Smith says a cracked tank typically means replacing the whole water heater.
• Not a leak at all: A. O. Smith notes condensation is often mistaken for a leak, especially on a new heater or with very cold incoming water.

The relief valve (T&P valve)

The temperature and pressure relief valve is a safety device that limits temperature and pressure in the tank, A. O. Smith explains; when pressure reaches its rating, it opens slightly to relieve it. Water from its pipe is a warning, not just a nuisance.

• Never cap or plug it. Rheem’s manuals say never plug the relief valve outlet, and no valve or restriction may be installed in its discharge line.
• Occasional dripping can come from thermal expansion in a closed system. Rheem and A. O. Smith both point to a properly sized and charged expansion tank as the fix.
• Rheem says to lift and release the valve’s lever at least once a year to make sure it works. If it keeps dripping afterward, have it checked.

Protecting the floor

Where a leak could cause damage – in a closet, attic or finished basement – Rheem recommends a drained catch pan under the heater. Water leak sensors with alarms are another inexpensive layer of warning.

Earthquake strapping

In California, new and replacement water heaters must be anchored or strapped to resist falling in an earthquake, and sellers must certify to buyers that water heaters are braced, according to the California Seismic Safety Commission. An unbraced heater that falls can cause gas leaks, electrical hazards and water damage. Other states and cities in earthquake areas have their own rules; ask your plumber or building department.

Repair or replace?

Fittings, the drain valve and the relief valve can be replaced. A leaking tank cannot be repaired. The U.S. Department of Energy puts a storage water heater’s life at about 10 to 15 years, so a leak on an older heater is usually the signal to replace it. Compare options in our tank vs tankless guide, and ask about permits – water heater replacements often need one.