Bock Water heaters 119ST, Instruction Manual

Page: 5 / 12

INSTALLATION
There are many factors to consider when installing a storage tank. How will the system be
used? What are the hot water demands of the system? Why is a storage tank being installed?
Are the peak demands frequent such as a home with multiple showers or very intermittent
such as a church kitchen? The answers to these questions will help you determine what your
system should look like. The following drawings will show you some typical installations.
If your system does not fit one of these applications, remember the basic principles that are
illustrated here:
1. Hot water should exit the top of the tank.
2. If cold water enters the storage tank, it should enter through a fitting on the lower side of
the storage tank. Examples: boiler system, reverse storage system
3. A circulator suitable for use with potable water must be used to move cool water from the
storage tank to the heat source during stand-by periods.
4. The circulator will normally draw cool water out of a large fitting near the bottom on the
side of the storage tank and return it to the heat source. (The reverse storage system is an
exception to this.)
5. Heated water will return to the storage tank from the heat source to the large fitting nearer
the center of the storage tank or the large fitting near the top of the side.
DRAWING #1
Drawing #1 shows a typical
installation for a home or business
with high peak loads such as
multiple showers in the morning.
This drawing also shows an
optional bypass system (N.C.
Valve) to allow the storage tank to
be isolated from the system. Cold
water is connected to the inlet of
the water heater. Hot water is
plumbed from the hot water outlet
of the water heater to the middle
fitting on the side of the storage
tank. Hot water for the home will
be drawn off the top of the storage
tank. The lower fitting in the side
of the storage tank is connected
to the cold water inlet or
recirculation return/drain valve fitting of the water heater with a circulator. The circulator is
controlled by the storage tank aquastat and draws cool water off the bottom of the tank and
returns it to the water heater for reheating. As a result, heated water is returned from the
water heater to raise the temperature of the storage tank. A check valve is also used to
prevent cold water entering the water heater from flowing backwards through the circulator
and diluting the hot water in the storage tank.
Storage Tanks Page 5
VALVE N.O.
VALVE N.C.
CIRCULATING
TANK
AQUASTAT
CHECK VALVE
STORAGE
HOT WATER
OUT
RECIRCULATION
PUMP
(OPTIONAL)
RETURN
COLD WATER
SUPPLY
HEATER
WATER