What
is a dip tube, replacing and how it effects water heater performance
Water heater dip tube is the long plastic rod that runs from the top of
the heater and ends few inches from the bottom of the tank. Dip tube is
also another name for
cold water inlet extension, as it brings the cold water to the
storage tank, allowing the proper flow and heat transfer.
It is designed to keep the cold water at the bottom of the tank as the
burner or main heating element is situated there, while separating
cold
from hot area located at the top of the unit.
When the tap is open, pressure inside the plumbing forces
cold water into the heater tank through the dip tube. This pushes
hot
water out of the tank toward the hot faucet.
Some manufacturers are designing dip tubes in a way to ensure better
heater performance by reducing sediment deposits at the
bottom of the tank and increasing turbulence.
Dip tube has to be checked regularly, and if you notice cracked or
broken
tube, it is time to replace it. Broken tube can affect
heating operation and efficiency, as the cold water will go directly to
the hot tap
without being heated.
Water
heater dip tube is made of polypropylene material and lower quality
ones
might react with the hot
water and start falling apart. The dip tube will deteriorate into chips
or white
sludge that sticks to the interior of the tank and plumbing
while clogging faucets and reducing heaters'
efficiency.
How
to Replace Water Heater Dip Tube
Dip tube is located at the top of the heater and it is easy
to approach for repair/replacement or inspection. Follow the steps
bellow for successful dip tube replacement:
Turn the power off on the heater
Close the water inlet on the main valve
Drain the cold water supply line
It is not necessary to completely drain the tank.
Drain only a gallon or two to avoid accidental spilling on top
of the heater.
Using a pipe wrench unscrew the pipe
connector. If dip tube is attached to the steel inlet nipple, simply
remove the nipple and the tube will come right out. Sometimes it is
difficult to remove the nipple if the heater is old and
there is heavy corrosion.
Remove the ring gasket.
Take the dip tube from inside the cold water intake
hole and pull it out (you can use pliers).
Install the new tube in reverse order and don't
forget to bring the rubber ring gasket back inside the connector
sleeve. Apply Teflon tape to secure the connection.
Turn the heater on.
Note: Do not apply heat to the hot or cold water connections as it will
permanently damage dip tube.
The problem with a conventional dip tubes is a weak water diffusing
action, interference in heat transfer, lower tank capacity, part
failure and its inability to make a turbulence flow and keep the
system efficient.
How
different dip tube design solves sediment problem
All big heater manufacturers like AO Smith, Bradford White,
Rheem are now using its patented
technology to solve or reduce problem with hard water and deposits at
the bottom of the tank it creates. This new design tube is few times
better than standard water heater dip tube.
Bradford White for example, is using The Hydrojet dip
tube, with a series of concentric "jet ports", in order to create
turbulent action inside the tank. The main purpose of these specially
designed and located ports on the dip tube is to redirect the water
flow with the dynamic action.
AO Smith is using Dynaclean
system with an innovatively designed dip tube made of long lasting PEX
cross-link polymer. Rheem is using Everkleen
system.
All of them are using the same way of protection and to enhance
performance; when water is drawn through the dip tube, turbulent action
puts
dissolved minerals and lime into suspension, preventing from settling
to the bottom of the tank and other elements.