To avoid confusion over debits and credits, avoid thinking of them in the way that they are used in everyday language, which often refers to a credit as increasing an account and a debit as decreasing an account. For example, if our bank credits our checking account, money is added to it and the balance increases.
One way to reduce the frequency of this occurrence is to maintain an air pocket at the top of the water heater tank. This air pocket will form in the tank by design - however, it will be reduced over time by the everyday use of your water heater. To replenish this air pocket: Turn off the water heater.
Reasons Why the Mpemba Effect Happens. 1  increased convection in hot water. 2  increased tendency of cold water to supercool compared with hot water. 3  potential different amounts of dissolved gases in cold water compared with hot water. 4  effect of frost formation -- hot water tends to freeze from the bottom while cold water tends to freeze from the top.