CIRCULATING PUMP
A circulating pump is used when a system requires a circulating loop or there is a storage tank used in conjunction with the boiler. Install in accordance with the current edition of the National Electrical Code, NFPA 70 or the Canadian Electrical Code, CSA C22.1. All bronze circulating pumps are recommended for use with commercial boilers. Some circulating pumps are manufactured with sealed bearings and do not require further lubrication. Some circulating pumps must be periodically oiled. Refer to the pump manufacturer’s instructions for lubrication requirements.
XB HYDRONIC BOILERS: The circulating pump is not provided on standard models (optional) and must be obtained and installed in the field.
XW HOT WATER BOILERS: The circulating pump is integral to the XW models. This pump has been lubricated at the factory, and future lubrication should be in accordance with the motor manufacturer’s instructions provided as a supplement to this manual.
PRIMARY SYSTEM CONTROL
All XP boiler installations require a “Primary System Control” that senses and reacts to water temperature inside the storage tank on domestic water applications or in the return line on primary/ secondary hydronic heating systems. The Primary System Control will activate and deactivate boiler heating cycles based on its setpoint and current system water temperature. There are three suitable methods to configure a Primary System Control. One of these three methods must be used.
1.The Primary System Control can be the boiler’s control system working with the factory supplied Header Sensor, installed inside the storage tank on domestic water applications or in the return line on primary/secondary hydronic heating systems.
2.Alternatively, the Burner Control system can be used as a Primary System Control. It will also provide boiler status and error reporting. Multiple boilers can be joined together to heat a system instead of a single, larger burner or boiler. Using boilers in parallel is more efficient, costs less, reduces emissions, improves load control, and is more flexible than the traditional large boiler.
3.MB2 and COM2 ports can be used for Building Management Systems.
INTERNAL CONTAMINANTS
The hydronic system must be internally cleaned and flushed after a new or replacement boiler has been installed, to remove contaminants that may have accumulated during installation. This is extremely important when a replacement boiler is installed into an existing system where Stop Leak or other boiler additives have been used.
Failure to clean and flush the system can produce acid concentrations that become corrosive, and leads to heat exchanger failure.
All hot water heating systems should be completely flushed with a grease removing solution to assure trouble-free operation. Pipe joint compounds, soldering paste, grease on tubing and pipe all tend to contaminate a system
Failure to flush contaminants from a system can cause solids to form on the inside of boiler exchangers, create excessive blockage of water circulation, deterioration of the pump seals and impellers.
HOT WATER BOILER SYSTEM - GENERAL WATER LINE CONNECTIONS
Piping 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 piping be installed and connected as shown on the diagrams. Check the diagrams to be used thoroughly before starting installation to avoid possible errors and to minimize time and material cost. It is essential that all water piping be installed and connected as shown on the diagrams. See Figure 78 on Page 80 and Figure 79 on Page 81.
CLOSED WATER SYSTEMS
Water supply systems may, because of code requirements or such conditions as high line pressure, among others, have installed devices such as pressure reducing valves, check valves, and back flow preventers. Devices such as these cause the water system to be a closed system.
THERMAL EXPANSION
As water is heated, it expands (thermal expansion). In a closed system the volume of water will increase when it is heated. As the volume of water increases there will be a corresponding increase in water pressure due to thermal expansion. Thermal expansion can cause premature failure (leakage). This type of failure is not covered under the limited warranty. Thermal expansion can also cause intermittent Temperature-Pressure Relief Valve operation: water discharged from the valve due to excessive pressure build up. This condition is not covered under the limited warranty. The Temperature-Pressure Relief Valve is not intended for the constant relief of thermal expansion.
A properly sized thermal expansion tank must be installed on all closed systems to control the harmful effects of thermal expansion. Contact a local plumbing service agency to have a thermal expansion tank installed.
PRESSURE RELIEF VALVE
An ASME rated pressure relief valve is furnished with the boiler. A fitting for the relief valve is provided in the top of the boiler. Never operate the heating elements without being certain the boiler is filled with water and a properly sized pressure relief valve is installed in the relief valve opening provided.
The pressure rating of the relief valve should be equal to or less than the rated pressure capacity of any component in the system including the boiler. Should the valve need to be replaced, call the toll free phone number listed on the back of this manual for further technical assistance
