If you smell gas near a gas water heater, leave the house and call the gas utility from outside. Do not try to relight it.
Gas water heaters
Many older gas heaters have a small pilot flame that lights the burner. If it goes out, the heater stops heating. Newer models use electronic ignition and may show an error light instead.
- Check whether other gas appliances are working
- Look for a status light or error code on the gas control
- Follow the lighting instructions on the heater’s label only if you are comfortable doing so and smell no gas
Electric water heaters
Electric heaters use one or two heating elements controlled by thermostats. A tripped breaker, a failed element or a reset switch that has shut the heater off for safety will all stop the hot water.
If the breaker trips again after it is reset, leave it off. Repeated tripping points to a fault that needs to be found, not reset.
Tankless water heaters
A tankless unit may shut down because of an error, a clogged inlet filter, scale in the heat exchanger or too little gas supply. Most show an error code that narrows down the cause.
When professional help makes sense
If the pilot will not stay lit, the breaker keeps tripping, there is water around the heater or the unit is showing an error you cannot clear, it is time for a diagnosis. Working on gas controls or electrical components is not a safe homeowner task.