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Water heater leaking or relief valve dripping.

A licensed plumber should install tanks, regulators and relief valves, and a credentialed tester should test or repair backflow assemblies.

Customers put it like this

  • Water under the water heater
  • The pipe on the side of the heater drips
  • Hot water shot out of the relief pipe
  • The backflow device is spitting water
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Stop first if

  • Someone has capped or plugged the relief valve or relief pipe on a working heaterTreat it as an explosion risk. Keep people clear and call a licensed plumber now. Turn the heater off only if it can be done without risk.
  • Hot water is pouring from the relief valveKeep clear of the discharge because it can scald. Turn the heater off only if it can be done without risk. Call a qualified technician now.
  • You smell gas, including a rotten-egg smell near the heaterLeave the building now. From outside, call emergency services or the gas utility.
  • Water is standing around a heater that has powerStay out of the water. Shut off power only if it can be done without risk. Otherwise call the electric utility or a licensed electrician.
01

Ask on the call

6

Homeowner? These are the questions a good technician will ask you. Having the answers ready makes the first visit count.

  1. Is it a slow drip, short spurts, or a big flow of hot water?
  2. Does it happen while the water is heating, or all the time?
  3. Has anyone capped or plugged the discharge pipe?
  4. Is there a small tank on the cold line near the heater?
  5. Is there a pressure regulator, softener or check valve on the water line?
  6. How old is the heater?
02

Bring

5
  • Pressure gauge with a maximum-reading pointer
  • Air gauge for the expansion tank valve
  • Thermometer
  • Gloves and eye protection
  • Flashlight
03

Check on site

6
  1. Find where the water comes from: relief line, a fitting or the tank body. Look for any cap or plug.
  2. List each one-way device on the line. Ask the water utility about the meter.
  3. Fit a gauge at a hose bibb or heater drain. Record static with the heater idle. Then watch it through a heat-up while no water is used.
  4. A rise only during heating may point toward trapped expansion. High pressure all the time may point toward supply or the regulator.
  5. If a tank is present, turn heater power off first. Drain the water side down to no pressure, then read the air charge.
  6. A qualified person works the relief lever only with the discharge piped to a drain and nobody in its path.
04

Keep on the record

5
  • Pressure readings at rest and across a heating cycle
  • Photo of the discharge line from the valve to its end
  • List of one-way devices and regulators
  • Expansion tank air reading and incoming static
  • Heater nameplate, plus the test tag on any backflow assembly

General guidance for a qualified person, not a finding about any home. The person on site decides.