Why is My Water Heater Making Noises?

Every so often we get the “it sounds like my water heater is going to explode” call. Fortunately, the days of exploding water heaters are long gone: thank you temperature and pressure relief valve!  That said, there are still three water heater related noises that may raise the red alert:

1. The “mysterious drip” sound in the wall.  Only last week we had a customer who was convinced a pipe in the wall was leaking when they turned on their bathroom sink faucet.  I had a hunch: I asked them if it happens when they turn on the hot or cold water. Ah ha! As I suspected it only happened when they used the hot water. The drip, drip, drip noise was the result of the hot water lines moving ever-so-slightly due to thermal expansion in the pipe and rubbing against the wood in the walls. This is typically harmless.

  1.  The ominous “drip in the water heater” sound. This sound, while much less common, does cause many homeowners to think their water heater is leaking.  Typically it happens when the water heater first fires up and the warm exhaust air causes condensation in the vent pipe that drips back down onto the burner (think warm breath on a cold day making those little clouds from the mouth). Fortunately, as soon as the vent pipe warms the condensation stops.  Easy enough.
  1.   Snap-crackle-pop noise. No, we’re not talking about cereal. This noise is a real concern because it means that your water heater is holding sediment.  Over time the minerals in normal water builds up on the bottom of the tank thereby reducing the lifespan and efficiency of your water heater. Lime and other mineral deposits from the water solidify and build a thick cake at the bottom of the tank and water gets trapped inside this substance. When the water heater turns on these pockets of water expand and pop and crack. While this issue poses no immediate risk of damage to the tank it can result in expensive repairs of the control valve and, to the dismay of many a homeowner, decrease the efficiency and lifespan of your water heater.

Here we have a simple remedy: schedule and perform a regular flushing your water heater to clean out any sediment buildup.

Takeaway: next time you are … bored … take a walk downstairs and listen to your water heater. It may have a story to tell!