Hot Water Supply Applications; Water Line Connections; Hard Water Conditions - A.O. Smith DB/DW-720-1810 User Manual

HOT WATER SUPPLY APPLICATIONS

Cer-Temp 80 Recovery Systems

WATER LINE CONNECTIONS

This section provides detailed installation diagrams for typical
methods of application for the unit using a Cer-Temp 80 Recovery
System (for one temperature water).
This equipment must be protected against loss of water or loss of
water flow by the installation of a safety flow switch in the outlet
piping from the boiler. Piping and wiring diagrams show the
application of this accessory for this purpose.
These diagrams will serve to provide the installer with a reference
for the materials and methods of piping necessary for installation.
It is essential that all water and gas piping, vent connections,
electrical wiring, and check and flow regulating valves be installed
as shown on the diagrams.
ONE DURA-MAX (MODEL DW) COMMERCIAL BOILER WITH VERTICAL TANK
TO PREVENT CONDENSATION THE MINIMUM BOILER INLET TEMPERATURE IS 100°F (38°C)
INSTALL IN ACCORDANCE WITH ALL LOCAL CODES.
SEE PAGE 31 FOR
ADDITIONAL PIPING INFORMATION.
Where excessive heat exchanger condensation exists due to
continued low water inlet temperatures, a bypass balance loop
must be installed (see page 15).

HARD WATER CONDITIONS

Where hard water conditions exist, water softening or the threshold
type of water treatment is recommended. This will protect the
dishwashers, coffee urns, water heaters, water piping and other
equipment. When water softening or water treatment is not
practical, a comparatively easy method of periodic lime removal
from the unit must be employed.
Lime accumulation can reduce the life of the equipment, reduce
efficiency and waste fuel. Boiler failure due to lime or scale build-
up voids the warranty.
These units are so constructed that lime removal is simple and
complete, see PREVENTIVE MAINTENANCE.
CAUTION
SAFETY FLOW SWITCH AS SHOWN TO PROTECT THE BOILER IN CASE
OF WATER SERVICE INTERRUPTION OR CIRCULATOR FAILURE.
* SAFETY RELIEF VALVE RATING SHOULD NOT EXCEED PRESSURE
CAPACITY OF ANY COMPONENT IN THE SYSTEM.
PUMP MUST BE RATED FOR SYSTEM OPERATING TEMPERATURES
AND PRESSURE.
SEE TABLE 7 FOR GUIDE TO PIPE AND PUMP SIZING.
+ BALL VALVES ARE SHOWN FOR SERVICING BOILER, HOWEVER,
LOCAL CODES SHALL GOVERN THEIR USAGE.
27
WARNING
IMPORTANT
CAUTION