My gas water heater makes noises whenever hot water has been drawn, and for a brief period of time while it is re-heating. Does that mean it is about to conk out, or what could cause this noise?

frankvan, check this site and scroll down to the gas water heater part. Is your water heater 17 - 20 years old? If so, it's time for a new one!

Thanks, Tree. I'll have to take a look and see when it was installed, but I doubt it was that old, so I'll try draining the sediment out and keep an eye on it.

Noise coming from gas water heaters can often be caused by the sediment build up in the bottom of the water heater. As the burners heat the bottom of the tank gas bubbles form under the sediment. The thumping and popping noises are created by the gas bubbles escaping from under the sediment. Sizzling noises can be caused by condensation dripping onto the hot burner.

You may try completely removing the drain stem, unscrewing it from the bottom of the tank (with the burner off) and opening the valve to flush water through it. Easier if it's not located inside your house.