Crown Boiler CWI103 Installation Instructions Manual Download

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VIII System Piping

Standard Piping

Figure 11 shows typical boiler system connections on a single zone system. Additional information on hydronic system

design may be found in

Installation of Residential Hydronic Systems

(Pub. #200) published by the Hydronics Institute in

Berkeley Heights, NJ. The components in this system and their purposes are as follows:

1) Relief valve (Required) - Mount the relief valve on the right side of the boiler as shown in Figure 1 using the 3/4 nipples

and elbow provided. The relief valve shipped with the boiler is set to open at 30 psi. This valve may be replaced with one

having a pressure up to the “MAWP, WATER” shown on the rating plate. If the valve is replaced, the replacement must

have a relief capacity in excess of the DOE heating capacity for the boiler.

Pipe the discharge of the relief valve to a location where water or steam will not create a hazard or cause property damage

if the valve opens. The end of the discharge pipe must terminate in an unthreaded pipe. If the relief valve discharge is

not piped to a drain it must terminate at least 6 inches above the floor. Do not run relief valve discharge piping through an

area that is prone to freezing. The termination of the relief valve discharge piping must be in an area where it is not likely
to become plugged by debris.

2) Circulator (Required) - Although the circulator is shipped on the boiler return, it can be installed on the boiler supply. If

the circulator is moved to the supply, it should be positioned just downstream of the expansion tank as shown in Figure

11.

3) Expansion Tank (Required) - If this boiler is replacing an existing boiler with no other changes in the system, the

old expansion tank can generally be reused. If the expansion tank must be replaced, consult the expansion tank

manufacturer’s literature for proper sizing.

4) Fill Valve (Required) - Either a manual or automatic fill valve may be used. The ideal location for the fill is at the

expansion tank.

5) Automatic Air Vent (Required) - At least one automatic air vent is required. Manual vents will usually be required in

other parts of the system to remove air during initial fill.

CAUTION

• INSTALL BOILER SO THAT THE GAS IGNITION SYSTEM COMPONENTS ARE PROTECTED

FROM WATER (DRIPPING, SPRAYING, RAIN, ETC.) DURING APPLIANCE OPERATION AND

SERVICE (CIRCULATOR REPLACEMENT, ETC.).

• OPERATION OF THIS BOILER WITH CONTINUOUS RETURN TEMPERATURES BELOW 120°F

CAN CAUSE SEVERE HEAT EXCHANGER CORROSION DAMAGE.

• OPERATION OF THIS BOILER IN A SYSTEM HAVING SIGNIFICANT AMOUNTS OF DISSOLVED

OXYGEN CAN CAUSE SEVERE HEAT EXCHANGER CORROSION DAMAGE.

• DO NOT USE TOXIC ADDITIVES, SUCH AS AUTOMOTIVE ANTIFREEZE, IN A HYDRONIC

SYSTEM.

DANGER

•  PIPE  RELIEF  VALVE  DISCHARGE  TO  A  SAFE  LOCATION.
•  DO  NOT  INSTALL  A  VALVE  IN  THE  RELIEF  VALVE  DISCHARGE  LINE.
•  DO  NOT  MOVE  RELIEF  VALVE  FROM  FACTORY  LOCATION.
•  DO  NOT  PLUG  RELIEF  VALVE  DISCHARGE.