Westinghouse WBCNG399WPU Installation Instruction
22
WHL-016 REV. 3.4.15
F. HYDRONIC PIPING WITH CIRCULATORS, ZONE VALVES, AND MULTIPLE BOILERS
This boiler is designed to function in a closed loop hydronic system. It is recommended to install a temperature and pressure gauge (not
included with the boiler) to allow the user to monitor system pressure and outlet temperature from the boiler. It is important to note that
the boiler has a minimal amount of pressure drop that must be calculated when sizing the circulators. Unless the system has a closed
type expansion tank, each boiler installation must have an air elimination device that will remove air from the system.
Install the boiler so the gas ignition system components are protected from water (dripping, spraying, etc.) Allow clearance for basic
service of boiler circulator, valves and other components.
Observe the minimum 1” clearance around all uninsulated hot water pipes when openings around pipes are not protected by non-
combustible materials.
On a boiler installed above radiation level, some states and local codes require a low water cut off device, which is an optional part
available through Westinghouse (Part # 7600P-104 for 055
included with the boiler) to allow the user to monitor system pressure and outlet temperature from the boiler. It is important to note that
the boiler has a minimal amount of pressure drop that must be calculated when sizing the circulators. Unless the system has a closed
type expansion tank, each boiler installation must have an air elimination device that will remove air from the system.
Install the boiler so the gas ignition system components are protected from water (dripping, spraying, etc.) Allow clearance for basic
service of boiler circulator, valves and other components.
Observe the minimum 1” clearance around all uninsulated hot water pipes when openings around pipes are not protected by non-
combustible materials.
On a boiler installed above radiation level, some states and local codes require a low water cut off device, which is an optional part
available through Westinghouse (Part # 7600P-104 for 055
– 110 models, 7600P-990 for 155 – 399 models). Check with local codes for
additional requirements. If the boiler supplies hot water to heating coils in air handler units, flow control valves or other devices must be
installed to prevent gravity circulation of boiler water in the coils during the cooling cycle.
Chilled water medium must be piped in parallel with, and isolated from, the boiler. Freeze protection for new or existing systems must
use glycol that is specifically formulated for this purpose. Antifreeze must include inhibitors that will prevent the glycol from attacking the
metallic system components. Make certain that the system fluid is checked for the correct glycol concentration and inhibitor level. The
system should be tested at least once a year and as recommended by the producer of the glycol solution. Allowance should be made
for the expansion of the glycol solution in the system piping. Example: 50% by volume glycol solution expands 4.8% in volume for a
temperature increase from 32
installed to prevent gravity circulation of boiler water in the coils during the cooling cycle.
Chilled water medium must be piped in parallel with, and isolated from, the boiler. Freeze protection for new or existing systems must
use glycol that is specifically formulated for this purpose. Antifreeze must include inhibitors that will prevent the glycol from attacking the
metallic system components. Make certain that the system fluid is checked for the correct glycol concentration and inhibitor level. The
system should be tested at least once a year and as recommended by the producer of the glycol solution. Allowance should be made
for the expansion of the glycol solution in the system piping. Example: 50% by volume glycol solution expands 4.8% in volume for a
temperature increase from 32
o
F to 180
o
F, while water expands 3% with the same temperature rise.
G. PIPING DETAILS
Mixing valves are required for the protection of low temperature loops.