Water Heater


You hear them in the middle of the night. Those snap, crackle and pops that come from the pipes and water heater making noises. You are told that they are harmless but how can you tell that you water heater noises are nothing serious? Here’s How!

The are a variety of sounds created by new or existing water heaters include:

  • Loud hammering or banging
  • Light ticking
  • Low rumbling
  • Intermittent pops
  • Hissing or sizzling


If it sounds like someone is banging on your pipes, you’ve encountered the “water hammer” effect. A sudden increase in pressure inside the pipe creates a shock wave that causes the pipe to move and bang against the wooden supports. This noise represents a potentially serious problem as the movement of the pipes can cause structural damage to your house. It is easily fixed by installing an arrestor to dissipate the effects of the pressure change or call a professional plumber to do it for you.


Minor expansion and contraction in the water pipes can lead to a ticking noise as the pipes tap against their strap supports. One other possibility is the heat traps installed on the unit. A small metal ball in this device will rattle as it, too, is expanded and contracted by the heat of the appliance.


The sacrificial aluminum rod, or anode, in your water heater corrodes to form aluminum hydroxide. This compound then clogs the heater drain resulting in a rumbling sound. To solve this problem, drain and flush the tank. Also use a commercial deliming solution to clean the anode of any large buildup of deposits.

Intermittent Popping

Calcium carbonate, or lime, is deposited on all exposed, internal surfaces of your water heater tank as well as the sacrificial anode. Water can be trapped under these deposits. As the water is heated, it expands and is released from under the lime deposit, causing the popping noise. Again, flushing the system and removing the deposits from the anode will solve this minor problem


This sound is more worrisome than a real problem. In a gas heater, as the hot gases are vented, water vapor will condense on the exterior of the flue and then drip onto the hot exterior of the heater. the characteristic hissing or sizzling sound is thus created. This sound is merely a nuisance and needs no remedy. Do check, however, that the water is not due to a leak in the system.

In conclusion, most water heaters making noises are relatively easy fixes and harmless. Good luck diagnosing the particular noise that your water heater is making!