Short answer: For an electric water heater, check the breaker and the reset button on the heater. For a gas water heater, check that the gas is on and the pilot light is lit. If hot water runs out fast or is only lukewarm, sediment, a failed heating element or a broken dip tube may be the cause. If you smell gas, leave and call the gas company.
Waking up to no hot water is frustrating. Sometimes the fix is simple. This guide explains what to check when you have no hot water, and when to call a plumber.
If you smell gas near a gas water heater, do not try to light the pilot. Leave the home and call your gas company or 911 from outside.
Electric water heaters
- Check the breaker for the water heater. If it tripped, reset it once.
- Look for a red reset button behind the upper panel. Some trip when the water gets too hot. Switch off power before opening panels.
- If it trips again, or there is still no hot water, a heating element or thermostat has likely failed.
- Lukewarm water often means the upper or lower element has failed.
Gas water heaters
- Make sure the gas valve to the heater is on, and other gas appliances work
- Check whether the pilot light is lit, through the viewing window
- Relight it only by following the instructions on the heater’s label
- If it will not stay lit, the thermocouple or gas control may need replacing
- Check the vent is not blocked, which can trigger safety shutoffs
Hot water runs out too fast
- Sediment: minerals settle at the bottom of the tank and take up space. Flushing helps
- Broken dip tube: cold water mixes with hot at the top of the tank
- Heater too small: for your household’s hot water use
- Thermostat set too low
Tankless water heaters
- Check the display for an error code
- Make sure the flow is high enough to trigger heating
- Clean the inlet filter, and descale if you have hard water
- Check the gas supply or breaker
When to call a plumber
- The breaker or reset keeps tripping
- The pilot will not stay lit
- Water is leaking from the tank
- The heater is more than 10 to 12 years old
- You hear loud popping or rumbling
Read about water heater repair and replacement, a leaking water heater and tankless vs tank water heaters.
Quick answers: no hot water
Why do I have no hot water?
For electric heaters, a tripped breaker or reset, or a failed element. For gas heaters, the pilot or gas supply.
Why does my hot water run out so fast?
Sediment in the tank, a broken dip tube, a low thermostat or a heater too small for your use.
How do I reset my water heater?
Switch off power, remove the upper panel and press the red reset button. If it trips again, call a plumber.
Can I relight my water heater pilot light?
Only by following the label instructions, and never if you smell gas.
Who repairs water heaters?
A licensed plumber. Sifixit can connect you with a local plumber.
Related
- Water heater repair and replacement
- Water heater leaking
- Tankless vs tank water heater
- Plumbing near you
This guide covered no hot water. For more background, see the EPA’s WaterSense program, and if you need help, Sifixit can connect you with a local provider.
This guide is general information for homeowners, not professional, insurance or safety advice for your situation.
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