A.O. Smith TC-049-R2 manual Service Handbook, Residential Gas And Electric Water Heater, What

RESIDENTIAL GAS AND ELECTRIC WATER HEATER

SERVICE HANDBOOK

WHY WATER HEATER TANKS LEAK

WHAT	WHY	PREVENTION
Water	Water expands when it is heated	A Temperature and Pressure Relief
Pressure	(Thermal Expansion). Water	Valve limits pressure to a
	cannot be compressed.	maximum.
	Excessive Pressure in the tank	Adding a Thermal Expansion Tank
	causes failure of joints, welds or	limits pressure to near supply water
	gaskets.	pressure.
Condensation	Products of combustion contain	Install a water heater with capacity
(Gas Water	moisture. As the combustion	to minimize significant stored water
Heaters)	products cool the moisture	temperature drop during usage.
	becomes liquid – carbonic acid.	Store water at a higher temperature
	The acid attacks the metal.	– install a mixing valve to reduce
	Higher efficiency water heaters	danger of scalding.
	have cooler gases.
	Recommended water storage
	temperatures create cooler
	surfaces.
Contaminated	Bleaches, floor waxes,	Supply the heater with clean air.
Air	detergents, salt and many other	“Direct Vent” water heaters use air
	household products contain	from outside of the building for
	chemicals which, when drawn into	combustion.
	contact with a flame (a gas water
	heater uses 12 cubic feet of air for
	each 1000 BTU of heat
	generated). When these
	chemical vapors or dusts come
	into contact with a flame or
	electrical contact, various acids
	form. These acids attack the
	metal.
Soft Water	Soft water minimizes mineral	A metal “Anode” rod within the tank
	buildup within the tank. Minimal	helps to prevent internal corrosion.
	minerals maintain the water	Maintain the self sacrificing “anode”
	heater at high efficiency but may	rod by inspecting the rod annually
	also expose interior surfaces to	and replacing when large “gouges”
	corrosion. Mineral buildup in	appear in its surface.
	some heaters prevents them
	leaking while greatly reducing
	efficiency.

A.O. Smith Water Products Company	47	Training Department
©2002		Ashland City, Tennessee