Thermal Expansion and Water Heaters

Thermal Expansion and how it affects your water heaterexpansion tankamstrol-30-expansion-tank-a.55134307_std.

What is Thermal Expansion?

Thermal expansion is a word describing the science of water expanding in volume as it heated.

How does thermal expansion negatively affect your tank type water heater?

There are several ways that thermal expansion is detrimental to your water heater. Most steel tank type hot water heaters are mainly protected from rusting by a ceramic like glass lining and a sacrificial anode rod. As cold water enters the tank and is then heated up, the volume of the water increases. The now larger volume of water flexes and expands the glass lined steel tank. Steel and glass have a completely different coefficient of expansion rate, therefore they are always in a slight opposition of each other. In todays closed plumbing systems, closed plumbing means that this that this added volume of water has nowhere to go. The newly added volume of heated water, the excess water pressure pressing against the tank and the difference in the expansion and contraction rate of the glass like lining compared to that of the steel all contribute to the eventual cracking of the protective glass lining. When the glass lining cracks water penetrates into the steel rusting it out and sending the water heater into early premature failure by no fault of the hot water tank itself on its own.

How does thermal expansion affect your tankless water heater?

Other than the glass lining stress cracks of the tank type water heater, tankless water heaters suffer similar stresses from high pressure due to thermal expansion. The expanded water in the heater can cause it to malfunction of age prematurely.

Is thermal expansion dangerous to my hot water heater?

Yes! Thermal expansion can be very dangerous to my water heater and my health. The increase in pressure to the unprotected tank can cause the internal flue to collapse in on itself, thus cooling the products of combustion, potentially creating carbon monoxide. If the carbon monoxide enters the living area of a home, people could become seriously ill or die.

Please call BC Redi-Rooter Ltd plumbing, heating, gas fitting, and drain cleaning of the Lower Mainland and The Fraser Valley to make your home hot water installation safe!