WaterLogic WL400 Series, Service Manual

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WL400 Manual Page 14 – Revision: 5‐2‐2018
HOT TANK PRINCIPLES OF OPERATION
All Waterlogic Hot Tanks have a built in Vent or
Expansion Chamber in the top of the tank except for
WL270 (GF) units.
The Vent Chamber allows for expansion of the water
when it is heated.
The chambers are separated by a welded‐in tank
baffle.
Water always flows into the bottom of the tank and
out the top to the faucet.
The hot tank outlet tube has a restrictor in its base.
This ensures the reservoir is always full by allowing
more water in than out.
There is a small hole in the side of the tank outlet tube
that allows air and water to pass into the vent
chamber as it is heated.
Water in the vent chamber is suctioned back through
the outlet tube vent hole when water is dispensed.
Expansion of water as it is heated in the reservoir will
push the water out the faucet when the outlet tube
vent hole becomes plugged with debris or scale.
The small Outlet Vent Hole is susceptible to scale build
up and is a key indicator that descaling is required.
It is critical to descale the hot tank through the vent
line and outlet line on a regular basis to prevent this
problem.
Descaling through the inlet and/or outlet lines only
will not clean the vent chamber and outlet vent hole
properly.