Completely normal. Chances are it only ticks when hot water is running, that is because it needs to work to keep heating the water.
The ticking could be just the pipes expanding and contracting. Or, the heating elements could have a build up that occurs over time.
Get out of your house as quickly as possible and call the police. Someone has obviously planted a c4 charge in your water heater. To make it easier for the FBI compile a list of everyone who would have cause to harm you or your family in any way.
The cool water hitting your piping hot exhaust makes the metal contract (Shrink) and it makes a ticking noise.
american water heater company
makes the water stay at the set temperature longer plus keeps the water heater off longer.
Rheem
Mine doesnt but yours might because the spinning disk inside for measuring water is hitting something.
it really dpends on the speed of water.. but if the water is going fast... it would make a splash sound but if the water is going slow.. it can make a soft sound that are like music to your ears
American Water Heater
water
Sears makes Kenmore tanks
water heater