Water Heater Makes Noises

Problem: Water heater makes un-usual noises, which may include sizzling, popping, crackling, pounding, and rumbling sounds.

Background: Certain noises from a water heater may be normal, such as the expansion and contraction of metal parts during heating-up and cooling-down periods. Sizzling and popping sounds may be caused within the burner area by the formation of normal condensation during heating and cooling periods. Sediment build-up on the bottom of the tank may also create various noises (and if left in the tank, may cause premature tank failure).

 

What to do: If water heater is making crackling, sizzling, or popping noises, check to determine whether it is a leak or normal condensation (see Water Heater Leaks). In some cases the temperature-pressure (IF) relief valve may be dripping because the water supply system has pressure-reducing valves, check valves or back- flow preventers. When these devices are not equipped with an internal bypass and no other measures are taken, they can cause the water sys tem to close so it does not allow for the expansion of heated water In this case the IF valve will drip to relieve the excess pressure. Call a technician to install a bypass and/or an expansion tank to relieve the pressure from thermal expansion.
   In some cases, a TP valve may leak because the water heater temperature is set too high; in other cases, it is because the TP valve is bad. Too high of a temperature set ting can also cause pounding and rumbling or a surging sound in the heater.

Special advice: Sediment build-up in the tank can cause water heater noises as water droplets get under the sediment and convert to steam when heated. Drain the tank to clean; if the problem remains, con tract a technician to do a professional cleaning. Similar sounds can come from electric water heaters and are caused by scale-encrusted heating elements; in this case, the elements can be replaced. Sediment build-up can be reduced by regularly draining a few quarts of water every month from the drain valve at the lower front of the tank.

Helpful hint: The TP relief valve should be manually operated at least once a year. Check your owner’s manual for the recommended procedure. Make sure no one is near the outlet of the discharge line, and that extremely hot water discharged will not cause damage when discharged. (If the valve continues to release water after manually operating it, close the cold water inlet to the heater, following draining instructions in your manual, and contact a technician to replace the TP valve.)