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Hot Water System Life Expectancy – Trade secrets from a Master Plumber
One of the most expensive appliances in your home is likely to be your hot water system. It may have a life of 10-15 years. Depending on the type of system you own it could cost as much as $ 6000.00 to replace.
Would you like to know how you could make it last much longer?
Gas, electric and solar storage hot water systems have either a stainless steel tank or a vitreous enamel / glass-lined steel tank. The most common type is vitreous enamel / glass-lined steel tank. Normally, steel exposed to water will corrode through a process called electrolysis. Electrolysis can take place more rapidly if you use bore water or live in areas of hard water or mineralization. The vitreous enamel lining that is baked onto the inside surface of the steel tank prevents contact between the water and the surface of the steel.
As a secondary measure to protect glass lined steel tanks, a zinc alloy rod is fitted to the inside. This rod is called a sacrificial anode. The sacrificial anode protects the internal steel surface of the tank where the enamel lining has deteriorated or is pitted. Some hot water systems with additional cylinder warranty are fitted with two or more anodes.
Over time, the sacrificial anode becomes depleted. Once the anode has gone the process of electrolysis starts to eat away at the steel tank. However, the sacrificial anode can be replaced.
At the very top of the outer hot water system casing is a plastic access cap. Beneath the cap is the sacrificial anode nut. As the water in the tank can be under extreme pressure and at a high temperature it is best to have your licensed plumber replace the nut and anode. It doesn’t matter if there is not too much room above the hot water system as the replacement anodes are manufactured in a chain design.
If you have bore water or live in areas of hard water or high mineralization it is best to replace the anode once every 5 years. In all other areas it is best to replace the anode once every 10 years. You may find it could double the life of your storage hot water system.
Most people believe stainless steel tanks will last longer than glass lined steel tanks. However, it is worth noting that given that the stainless steel tanks are made of a much thinner grade of steel, they actually may not last as long as the enamel lined tank. There are two reasons for this. The first is that stainless steel does corrode and these tanks do not have a sacrificial anode. The second is they suffer more from the effects of expansion and contraction. This is accentuated in alpine regions where there is a colder incoming water temperature and a higher hot water demand.