Unlike tankless water heaters, standard tank-style water heaters use an insulated storage tank that holds anywhere from 30 to 80 gallons of water at all times. Water heaters are generally very reliable, but occasionally they do have problems, such as little or no hot water, rusty or smelly water, odd noises, and even leaks. If you need to inspect your water heater or make any kind of repair, be sure to turn off the power and/or the gas supply:

Turn off the power to an electric water heater by switching off the circuit breaker or removing the fuse on the water heater circuit in your home's breaker box or fuse panel.

Turn off the gas supply by turning the gas pilot control valve to the "pilot" setting on the water's gas valve.

Shut off the water supply to the water heater, if necessary, by closing the shutoff valve on the cold water pipe coming into the top of the heater tank. ​Do not turn off the water unless the water heater's power and gas are turned off.

The Problem: No Hot Water

There is nothing more shiver-inducing and unpleasant than a cold shower. If your water is not at an agreeable temperature, your water heater could be at the root of the problem. Key things to check on a gas water heater are the pilot, the thermocouple, and the gas control valve. On an electric unit, look at the thermostats and the heating elements.

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The Problem: Inadequate Hot Water

Inadequate hot water means your shower starts out hot and quickly turns cold. If your water heater is producing some hot water but not enough to meet your needs, there are several possible issues to address, including the temperature setting, the heating elements (electric heaters only), sediment in the tank, and a damaged or disconnected dip tube.

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The Problem: Rusty or Smelly Water

It can be quite worrisome when you turn on your faucet to discover discolored water or a nasty rotten egg smell. Pipe corrosion or bacteria buildup could be the possible perpetrators in this case.

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The Problem: Strange Noises

If you're hearing mysterious noises coming from your basement, it's probably just your water heater. A low rumbling or popping noise is the sound of boiling water. Excessive buildup of sediment in the bottom of the tank is causing the tank to overheat and, in turn, causing the water to boil. You'll have to remove the sediment by flushing your water heater.

Hissing sounds coming from a water heater could indicate a leak in the tank that's allowing water to drop down onto the burner. If the water heater is new or has been turned off for ​a while, and recently turned back on, there could be condensation from the bottom of the tank dripping onto the burner. This will subside once the tank fully heats up.

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The Problem: Water Leak Around Base of Heater

Any kind of leak is always a nuisance. A leaky water heater could be the result of a faulty T&P (temperature and pressure) relief valve, or a leak from a nearby plumbing connection or even the tank itself. A T&P valve and plumbing leaks can be repaired, but a leaky water heater tank cannot; the unit must be replaced as soon as possible.