Hot Water Heater Troubleshooting

Sediment buildup

When a water heater heats water, it causes calcium carbonate to precipitate out and settle to the bottom of the tank. Steam bubbles form under the sediment when the burners come on causing popping and other noises. Regular flushing helps prevent sediment buildup.

Not producing enough hot water

Check for a broken dip tube, wrong setting on the thermostat, a defective thermostat, burned out heating elements (electric) or a heavy buildup of sediment.

Dip tube

The dip tube is a long slender tube that fits down into the water heater's inlet and usually has a small hole about 6 inches from the top. The dip tube directs the incoming cold water down to the bottom of the tank. If the dip tube is broken, the incoming cold water can mix with the outgoing hot water and cause it to appear that your are running out of hot water.

Noisy tank

Noise coming from gas models can often be caused by the sediment buildup in the bottom of the tank. Steam bubbles form under the sediment. The thumping and popping noises are created by the bubbles escaping from under the sediment. Sizzling noises can be caused by condensation dripping onto the hot burner.

Thermal expansion

When water is heated, it expands. If the inlet to the heater is blocked by a check valve, pressure reducing valve or other device, the increase in volume simply travels back into the source. If the inlet is blocked, this increase in volume will cause an increase in pressure - sometimes to dangerous levels.

The T&P valve relieves this pressure by discharging some water. A thermal expansion tank can be installed in the line that will absorb the increase in volume, thus preventing the relief valve from discharging unnecessarily.

Water hammer

When water is traveling in the pipes, it has kinetic energy (energy of motion). When a valve shuts of suddenly, a shock wave results - causing a "hammering" sound.

Hammer most often occurs when a valve shuts off suddenly. commercial arrestors are available to combat this problem. They consist of a small air bladder within a cylinder plumbed to the piping system near the valve causing the problem. Some hardware stores carry these units. Sometimes if the piping is sagging, supporting the sagging pipe segments may resolve the problem.

Milky color

Water contains dissolved oxygen and other gasses. When water is heated, it has less ability to hold these gasses and when pressure is lowered as the water comes out of a tap, these gasses can form tiny bubbles, giving the water a milky appearance. Letting the water stand for a few minutes will allow these bubbles to rise and dissipate out of the water and it resumes its clear appearance.

I have a hot water recirculation line that doesn't seem to be working since my new water heater was installed.

Please see the article in our Frequently Asked Questions (FAQ) page for the answer.