PanicStation.org
UK USA
us Home & property emergencies water heater leaking • hot water heater leak • leaking water heater bottom • water heater relief valve leak • tpr valve dripping • water heater popping noise • rumbling water heater • banging water heater • sizzling near water heater • water near breaker panel • shut off water heater power • shut off gas water heater • shut off water supply valve • possible gas leak smell • carbon monoxide alarm • emergency plumber call • landlord maintenance emergency • prevent water damage now • water heater overheating signs • noisy hot water tank

What to do if…
your water heater starts leaking or making unusual popping noises

Short answer

Shut off the water heater’s energy source (electric breaker or gas shutoff) and close the cold-water supply valve to the heater. If you smell gas or a CO alarm goes off, leave the building and call 911 (or your gas utility from a safe location).

Do not do these things

  • Do not keep running the heater “to see if it stops”—leaks and loud popping can worsen quickly.
  • Do not touch the heater, wiring, switches, or panels while standing in water (shock risk).
  • Do not try to plug, cap, clamp, or block the TPR (temperature/pressure relief) discharge pipe.
  • Do not relight a pilot, reset controls, or operate electrical switches if you smell gas.
  • Do not try to “cool” an overheating heater with water or by opening valves—your job is to remove the heat source and get help.

What to do now

  1. Do a quick danger check first (30 seconds).
    • If you smell gas or a carbon monoxide (CO) alarm is sounding: get everyone outside into fresh air immediately. From outside, call 911 (and/or your gas utility’s emergency line).
  2. Turn off the heater’s power/heat source (without taking risks).
    • Electric water heater: switch OFF the dedicated breaker in your electrical panel (often labeled “Water Heater”). Do not do this while standing in water.
    • Gas water heater: set the control to OFF if available (otherwise follow the unit’s label to shut the burner off). If you can safely reach it, turn the manual gas shutoff valve so it’s perpendicular to the gas pipe.
    • Leave it OFF until it’s inspected—don’t relight/reset as part of the panic moment.
  3. Shut off the water feeding the heater.
    • Close the cold-water shutoff valve on the pipe entering the heater.
    • If you can’t find it or the leak is heavy, shut off your home’s main water valve.
  4. Protect people and property in the next 5 minutes.
    • Place a bucket/tray under the leak and use towels to channel water away from outlets, extension cords, and the heater’s electrical access panels.
    • Move anything stored nearby (boxes, chemicals, electronics) out of the wet area.
  5. If you see steam/hissing, violent discharge, or nonstop loud banging: back away and escalate.
    • If water or steam is forcefully discharging from the TPR pipe, or you hear violent noises, do not approach to “fix” it. If you can’t safely shut off fuel/power from a safe position, leave the area and call 911/building management.
  6. Call the right help.
    • If you rent: contact your landlord/property manager’s emergency maintenance line and tell them you’ve shut off power/gas and water.
    • If you own: call a licensed plumber. If there’s any gas/CO concern, also contact your gas utility.
  7. Capture quick evidence, then step back.
    • Take photos/videos of where it’s leaking from (top connections, base, TPR discharge) and any surrounding damage—useful for insurance and the repair tech.

What can wait

  • You do not need to diagnose whether it’s sediment, a failing tank, or a valve problem right now.
  • You do not need to drain the heater, test the TPR valve, or open access panels during the panic moment.
  • You do not need to decide on repair vs replacement today—focus on safe shutdown and stopping water flow.

Important reassurance

A leak or new popping noise feels alarming because it mixes hot water, pressure, and sometimes gas/electric power. Turning off the heater’s energy source and shutting off the water supply usually stabilizes the situation and prevents the most serious outcomes while you get help.

Scope note

This is immediate, harm-prevention guidance only. A professional may need to inspect safety devices, venting, and internal condition, then repair or replace parts safely.

Important note

This is general information, not a diagnosis. If there’s any sign of gas leakage or carbon monoxide risk, prioritize leaving to fresh air and contacting emergency services or your gas utility from a safe location.

Additional Resources
Support us