PanicStation.org
UK USA
us Home & property emergencies

What to do if…
your water heater is leaking, discharging water, or making loud banging noises

Produced and maintained by PanicStation.org Published: Last reviewed: Editorial policy USA guide

Short answer

Stay away from hot water, steam, standing water, and wet electrical equipment. If there is smoke, fire, a sounding carbon monoxide alarm, suspected carbon monoxide poisoning, or suspected escaping natural gas, leave immediately and, from a safe location, call 911; for a suspected natural-gas leak, also contact the gas utility as appropriate. Otherwise, stop using hot water, shut off the heater and its water supply only when safely accessible, and contact a qualified plumber.

Do not do these things

  • Do not touch, plug, cap, clamp, or block the temperature and pressure relief valve or its discharge pipe.
  • Do not walk through standing water to reach the water heater, electrical panel, or shutoff valves.
  • Do not operate lights, switches, appliances, garage-door controls, or a phone inside if you suspect a gas leak.
  • Do not relight a pilot, reset the heater, or restore power while it is leaking or repeatedly discharging water.
  • Do not open the drain valve, flush the tank, remove access panels, or attempt a repair while the heater may be hot or energized.
  • Do not handle gas fittings, electrical wiring, venting, heating elements, or safety valves.
  • Do not remain beside the heater to investigate violent banging, steam, rapidly flowing water, scorching, smoke, or unusual odors.

What to do now

  1. Move people and pets away from the heater, hot water, steam, and wet flooring. For fire, smoke, suspected gas, electrical arcing, or an immediate burn or shock risk, leave the building and call 911.
  2. Check only from a safe distance for a gas odor, hissing gas, a carbon monoxide alarm, smoke, or fire. If any is present, leave without touching switches or appliance controls. From a safe location, call 911; for suspected escaping natural gas, also contact the gas utility as appropriate.
  3. If no gas leak is suspected and the route and controls are dry, shut off the heater’s energy source. For an electric heater, switch off its labeled circuit breaker. For another heater type, follow its emergency shutdown instructions only if the correct control is clearly identified and safely accessible.
  4. Close the cold-water supply valve serving the heater if you can identify and reach it safely. If you cannot, close the home’s main water shutoff only if you already know where it is and can reach it without entering water or approaching another hazard.
  5. Keep clear of any relief-valve discharge pipe because released water can be very hot. Do not alter the valve or pipe, even if the discharge continues after the heater is shut down.
  6. For a small leak, protect nearby belongings and contain spreading water only when you can do so without touching hot water, wet electrical equipment, or the heater. Do not block a floor drain or any heater discharge pipe.
  7. From a safe position, note whether water appears to come from the tank body, a pipe connection, the drain valve, the relief-valve pipe, a condensate line, or elsewhere. Take photographs only if this does not delay safety steps.
  8. Contact a qualified plumber promptly. Report the heater type, the apparent leak location, whether water is dripping or flowing, whether a relief pipe is discharging, and whether the unit is making new or severe noises.
  9. If loud banging occurs without visible water, stop using hot water. If the noise is new, severe, repeated, or accompanied by leaking, discharge, steam, or unusual odors, shut down the heater when safe and arrange prompt inspection.
  10. If you rent, notify the landlord, property manager, or emergency maintenance contact after addressing immediate danger. State that the water heater is leaking, discharging, or making loud banging noises and whether its power and water have been shut off.

What can wait

You do not need to diagnose sediment, water hammer, excess pressure, condensation, a failed valve, a loose connection, or a damaged tank now. Flushing the heater, replacing parts, restarting it, choosing a replacement, completing detailed cleanup, and making insurance or repair-cost decisions can wait until the energy and water are controlled and the heater has been assessed.

Important reassurance

These signs can have several causes, and the cause cannot be confirmed from the noise or water alone. Creating distance, avoiding gas and electrical hazards, shutting the unit down safely, and arranging an inspection are useful first steps.

Scope note

This guide covers immediate safety and damage-limitation steps only. Diagnosis, repair, replacement, code compliance, gas work, electrical work, and decisions about continued use may require a licensed plumber, qualified water-heater technician, electrician, gas utility, landlord, or insurer.

Important note

This is general safety information, not plumbing, electrical, gas, insurance, legal, or other professional advice. Follow the appliance manufacturer’s instructions and directions from emergency services, utility providers, your landlord, and qualified local professionals.

Additional Resources

Closely connected guides that may be useful during the same situation or its immediate aftermath.

About this guide

This guide was produced and is maintained by PanicStation.org using its published editorial process. Official and specialist sources are checked where relevant, and AI-assisted tools may be used for drafting, organisation, and consistency checks. The site operator remains responsible for publication, revision, and removal decisions.

Support us