The most common type is the storage tank water heater. It works by keeping a reservoir of water (typically 40-80 gallons) constantly heated to a set temperature by a gas burner or electric heating elements. When you turn on the hot water tap, pre-heated water is drawn from the top of the tank, while cold water enters the bottom to be heated.

Sediment (like minerals and limescale) naturally occurs in water and settles at the bottom of the tank over time. This can cause:

 Reduced Heating Efficiency: The sediment layer acts as an insulator, forcing the heater to work harder and increasing energy bills.

Noisy Operation: Popping or rumbling sounds as heat tries to pass through the sediment.

Tank Damage: Sediment can corrode the tank lining and lead to premature failure. 

Regular maintenance is key. The most important task is to flush the tank annually to remove sediment buildup. Additionally, you should:

Test the Temperature & Pressure Relief (TPR) valve every six months.

Inspect the anode rod every 2-3 years and replace it if heavily corroded. The rod attracts corrosive elements to protect the tank itself.

Look out for these warning signs:

Age: If it's over 10 years old, efficiency drops and failure risk increases.

Rusty Water: Discolored hot water indicates internal tank corrosion.

Water Leakage: Any signs of leaking from the tank itself is a critical issue.

Insufficient Hot Water: Not being able to meet your household's demand could mean the tank is failing or too small.