reader writes in to say he bought a water heater and
expansion tank, after being told last year that was now
required, and had them installed by someone who was not
a licensed plumber.
expansion tank was mounted horizontally — just hanging
there, he said — on the water supply line above the
reader was concerned that the tank would cause stress on
the connection. After he called the home center, a
licensed plumber was dispatched and added some nylon
straps to support the tank and screwed the straps to a
one ever checked the water pressure at the faucets, nor
the limit on how much the expansion tank could hold.
reader believes the tank is full and says he fears that
if the straps gave way, or the tank spewed out of the
release valve, it would flood his basement, which has no
you heard of disasters occurring with expansion
tanks?" he asks.
expansion is the term used to describe the expansion of
water volume due to heating. All water heaters,
regardless of heat source — gas, oil, electric, solar
or indirect — can experience thermal expansion.
to water-heater manufacturer Bradford White Corp., a
thermal-expansion tank is a small, pre-pressurized tank
with a compressible air cushion (a diaphragm) that is
installed on the supply side (the cold-water inlet) of a
thermal expansion of the water creates excess pressure
within the heater, water is forced into the expansion
tank, keeping pressure levels within the normal
operating range of the heater.
the pressure within the heater normalizes, the water
within the expansion tank is forced back into the heater
by the diaphragm, and the potentially harmful effects of
the thermal expansion are eliminated.
suggestion: Call the manufacturer of your equipment and
ask questions. I have never heard of such disasters, but
if you’re worried, act. You’ll likely be told to
call a licensed plumber.
especially plumbers out there, have any helpful
in the usual manner — and thanks.