Installation Instructions, Circulating Pump

probe is not supplied with the GB models. A tank probe can be used as an option to control loop temperature and unit staging. Additionally, the Inlet Temperature Probe can be used as the loop thermostat in some heating (GB) applications. These types of controls connect to designated wires in the junction box at the rear of the boiler. Do not operate this boiler using the internal high limits only, you must use an operating thermostat as mentioned above.

Note: Additional 24V devices or Tank Probe must be identified using Dip Switches on Central Control Board before they are recognized as a part of the heating system. See table 5 and refer to "Multi-Stage Firing and Control System" on previous page for more information about dip switch settings.

CIRCULATING PUMP

The pump flow rate should not exceed the maximum recommended flow rate, see table 4.

FOR HOT WATER SUPPLY SYSTEMS (GW models), ordered with the circulator as an integral part of the boiler; the pump has been lubricated at the factory, and future lubrication should be in accordance with the motor manufacturer's instructions provided as supplement to this manual.

FOR HOT WATER HEATING SYSTEMS (GB models or GW models ordered without circulator), the circulator is NOT provided and must be field-installed.

LOW WATER CUTOFF (Not Supplied)

If low water protection is required by the authorities having jurisdiction, a low water cutoff switch should be installed next to the boiler in the outlet water line as shown in "HYDRONIC INSTALLATION" section. The switch should receive periodic (every six months) inspection to assure proper operation. A low water cutoff device of the float type should be flushed every six months.

DRAIN VALVE (Not Supplied)

Additional drain valves must be obtained and installed on each boiler and tank for draining purposes.

SAFETY RELIEF VALVES

Your local code authority may have other specific relief valve requirements not covered below.

WARNING

THE PURPOSE OF A SAFETY RELIEF VALVE IS TO AVOID EXCESSIVE PRESSURE WHICH MAY CAUSE TANK EXPLOSION, SYSTEM OR BOILER DAMAGE.

TO AVOID WATER DAMAGE A DRAIN LINE MUST BE CONNECTED TO A SAFETY RELIEF VALVE TO DIRECT DISCHARGE TO A SAFE LOCATION. A DRAIN LINE MUST NOT BE REDUCED FROM THE SIZE OF THE VALVE OUTLET AND IT MUST NOT CONTAIN ANY VALVES BETWEEN THE BOILER AND THE RELIEF VALVE OR THE RELIEF VALVE AND THE DRAIN EXIT. IN ADDITION, THERE SHOULD NOT BE ANY RESTRICTIONS IN A DRAIN LINE NOR SHOULD IT BE ROUTED THROUGH AREAS WHERE FREEZING CONDITIONS MIGHT OCCUR. DO NOT THREAD OR CAP THE DRAIN LINE EXIT. RESTRICTING OR BLOCKING A DRAIN LINE WILL DEFEAT THE PURPOSE OF THE RELIEF VALVE AND MAY CREATE AN UNSAFE CONDITION. INSTALL A DRAIN LINE WITH A DOWNWARD SLOPE SUCH THAT IT NATURALLY DRAINS ITSELF.

If any safety relief valve is replaced, the replacement valve must comply with the latest version of the ASME Boiler and Pressure Vessel Code, Section IV (HEATING BOILERS). Select a relief valve with a discharge rating NOT less than the boiler input, and a set pressure NOT exceeding the working pressure of any component in the system.

The storage tank temperature and pressure relief valve must comply with the applicable construction provisions of the Standard for Relief Valves and Automatic Gas Shut-off Devices for Hot Water Supply Systems, ANSI Z21.22 or CSA-4.4 (and latest addendums). The valve must be of the automatic reset type and not embody a single-use type fusible plug, cartridge or linkage.

FOR HOT WATER HEATING SYSTEMS, the boilers are shipped with a 50 psi pressure relief valve. This relief valve is factory installed in the water outlet header of the boiler, see figure 1.

FOR HOT WATER SUPPLY SYSTEMS, the boilers are shipped with a 125 psi pressure relief valve. This relief valve is factory installed in the water outlet header of the boiler, see figure 1.

This ASME-rated valve has a discharge capacity that exceeds the maximum boiler input rating and a pressure rating that does not exceed the maximum working pressure shown on the boiler rating plate.

In addition, an A.G.A. design-certified and ASME-rated temperature and pressure (T & P) relief valve must be installed on each and every water storage tank in the hot water supply system, see figures 11 and 13.

The T & P relief valve should have a temperature rating of 210°F (99°C), a pressure rating NOT exceeding the lowest rated working pressure of any system component, and a discharge capacity exceeding the total input of the water boilers supplying water to the storage tank.

Locate the T & P relief valve (a) in the top of the tank, or (b) in the side of the tank on a center line within the upper six (6) inches (15 cm) of the top of the tank. The tapping shall be threaded in accordance with the latest edition of the Standard for Pipe Threads, General Purpose (inch), ANSI/ASME B1.20.1. The location of, or intended location for, the T & P relief valve shall be readily accessible for servicing or replacement.