On an electric water heater, check the breaker and the reset button on the upper thermostat. On a gas unit, check that the pilot light is lit and the gas supply is on. If those are fine, the likely cause is a failed heating element, thermostat, thermocouple or gas valve, which a plumber can test and replace.
Reviewed by Ron Olsen, Master Plumber, certified in Washington
Why a Water Heater Stops Heating
- Tripped breaker or high-limit switch
- Electric units have a reset button that trips when the water overheats.
- Pilot light out
- On gas units, a worn thermocouple or a draft can put the pilot out and keep it from staying lit.
- Failed heating element
- Electric heaters have 1 or 2 elements. When one fails, hot water runs out quickly or stops.
- Faulty thermostat
- A failed thermostat stops calling for heat even when the water is cold.
- Tankless unit issues
- Low flow, mineral scale or an ignition fault can stop a tankless unit from firing. Check the display for an error code.
What You Can Safely Check
- Electric: check the breaker. Then, with the power off, press the red reset button behind the upper access panel.
- Gas: follow the relighting instructions on the unit's label. Don't relight it if you smell gas.
- Tankless: check the display for an error code and look it up in the manual.
- Make sure the thermostat setting hasn't been turned down.
When to Call a Plumber
Call a plumber if the breaker or reset button trips again, the pilot won't stay lit, you smell gas, or the unit is leaking. Repeated tripping usually means a shorted element or a failed thermostat.
The repair is usually part of water heater repair & replacement, which explains what the plumber does and what affects the cost.
Water Heaters by City
What our city pages say about water heaters:
- Wichita, KS: With a median home built in 1974, many water heaters and supply lines are past their typical life.
- Tukwila, WA: Apartments and older homes go through tanks quickly.
- St. George, UT: Tanks in 2000s homes are at the end of their life.
- Virginia Beach, VA: With a median home built in 1984, many water heaters and supply lines are due for replacement.
- Foothill Farms, CA: Older homes are on their third or fourth tank.
- Cheyenne, WY: Homes from the 1970s have been through several tanks.
- Palm Bay, FL: Homes from the 1990s are on their second or third tank.
- Carmel, IN: Large homes often have 2 tanks, now on their second or third.
Other Water Heater Repair & Replacement Problems
No Hot Water Questions
Why do some faucets have hot water but not others?
If only one fixture has no hot water, the problem is probably the mixing valve or cartridge at that fixture rather than the water heater.
How long does a water heater take to recover?
A typical tank heater needs roughly 30 to 60 minutes to reheat after the tank is emptied, depending on its size and fuel.