6

I have a relatively new water heater (installed by previous owner). I've only been in the house a few months and did not notice this noise until after being there a few weeks. What happens is after any amount of hot water has been run, a loud snapping/clicking noise can be heard from the water heater. Could something be wrong with it?`

Being that it is an electric water heater, I am wondering if it's the heating element turning on. However, like I said, I didn't hear it the first few weeks we were there

isherwood
  • 158,133
  • 9
  • 190
  • 463
Tanner
  • 185
  • 1
  • 1
  • 5

3 Answers3

4

You probably have sediment buildup in the bottom of the hot water heater. Pockets of water get trapped in the sediment/scale at the bottom of the hot water heater, turn to steam when it heats up, then "explode" causing the noises you are hearing.

You could try draining the water heater to get some of the sediment out, but honestly it's probably too late for that - might want to have a pro come out and take a look at it. It's not likely a critical issue, but it would be best to get that scale cleaned off to prolong the life of the unit.

Eric Petroelje
  • 9,729
  • 7
  • 42
  • 62
2

As Eric has said, this is almost certainly being caused by sediment build-up. The sediment is wet, and when the element turns on, it turns the nearby water trapped by the sediment into steam, and it pops. It's not very much different than popcorn popping.

I've copied the appropriate steps from another answer of mine (didn't want to link it since you only need to do about half of what the other guy needed to do.)

Flushing your water heater:

  1. Unplug your water heater.
  2. Attach a garden hose to the drain at the bottom of the water heater.
  3. Run the other end of the garden hose outside.
  4. Open the drain.

This will forcefully drain the water heater, and hopefully the city's water pressure will be able to get a decent amount of the sediment out of the bottom. Depending on how fast the water is flowing, let this continue for 1-5 minutes. Sometimes the drain can be pretty clogged up or the bottom quite full, and the water won't come out very fast, especially when you disconnect the city's water pressure.

If this does not solve your problem, you'll need to be ready to replace the water heater (the bottom element will fail if buried under sediment, and no bottom element means basically no hot water)... or you can do a more thorough cleaning by taking the bottom element out (see other answer for instructions) and wetvac'ing the sediment out, like so: www.youtube.com/watch?v=pt1M7qO6Lh8

Community
  • 1
Michael
  • 3,806
  • 4
  • 28
  • 28
0

It is probably a bimetal (disc) thermostat.

A bimetal disc thermostat functions via the thermal expansion and contraction of a bimetal disc that “snaps” from a convex to a concave shape at a set temperature. When the disc “snaps”, it either completes or interrupts a circuit.

For further details see for example

Frank Breitling
  • 101
  • 1