Hello everyone, I'm in need of some professional advice. We have a
water heater, it's:

- Not new, about 4 years old
- Electric (two heating elements)
- Big enough for our 4 member family, so it's not a mini model
- Located in the garage
- NOT connected to a water softener (we live in indiana, really hard
water here, it's on our list of things to buy)
- Been drained once in the last three months to replace a bad element,
but no solvents/vinegar used to dissolve calcium or anything

Recently I heard a sound coming from the water heater DURING USE,
perhaps from near the top. It's not as violent as a knock may sound,
but I don't know how to tell the difference between a knock and a
click! So it's one of the two. The sound does not seem to happen after
use, only during.

Any suggestions? I'm thinking of draining the tank tonight by turning
off power, cutting cold water supply, opening a hot water tap while
connecting a hose to the bottom valve of the water heater, then after
the pressure is gone opening the value to drain the liquid & loose
calcium deposits. But do you think this will help?

Any suggestions are much appreciated, thanks!

brad