Lennox International Inc GWB8-262E-2, GWB8-280E-2, GWB8-245E-2 Equipment and Optional Accessories

17 - EQUIPMENT AND OPTIONAL ACCESSORIES

EXPANSION TANK

Expanding water flows into expansion tank. Tank should be correct size. Tank is filled with air. As water expands it compresses air in the tank to form air pressure cushion. This “spring-like” cushion serves to maintain correct operating water pressure regardless of water temperature. This assures “full measure” of water, even in highest radiation unit of system. It also prevents blowing off of safety relief valve. Air in tank in beginning (with system filled with cold water) is sufficient for proper operation. Tank also serves as trap for excess air in system. Air would cause gurgling in pipes and in efficient circulation in radiators if left in system.

It is possible for tank to become “waterlogged” (filled with water). It can also become overfilled with air. This can hap- pen after filling system with new water. Fittings provided on tank and in line to tank are for bleeding off excess water or air.

When installing this tank, it is important:

1.Tank be higher than boiler top.

2.Pipe to tank continuously rises up to tank (so air can “bubble” up to it).

DIAPHRAGM TYPE EXPANSION TANK

Diaphragm type expansion tank takes place of conventional expansion tank. Carefully read instructions packed with your tank assembly.

Tank comes with 10-12 pounds per square inch air charge. This is the same as pressure produced in system by automatic fill valve. When system is first filled, tank will contain little or no water.

As water is heated its pressure increases. It expands into tank, compressing air in tank. Compressed air cushion permits water in system to expand as temperature changes. Diaphragm type tank can be mounted on air purger fitting or at any convenient place in supply or return line.

AIR ELIMINATING FITTING (AIR PURGER)

Air purger is used to remove excess air from system. It is installed in supply line. It will eliminate air from water before it reaches radiators and bleed off this air.

MAIN AIR VENT FOR DOWN FLOW SYSTEMS OR DIAPHRAGM TYPE EXPANSION TANK

Before system is filled with water, there is air in pipes and radiation units. Some of it will be trapped as system is filled . It is possible to eliminate most of this air through air vent on radiation units. Main air vent will speed and simplify this. Install on highest point in supply main when all radiation is below top of boiler.

AUTOMATIC FILL VALVE

For a safe, efficient operation, hot water system must be completely filled with water. Adding new water, when needed can be done manually (by use of hand valve in water supply line). Requires regular attention to system’s needs. Automatic fill valve accomplishes this without atten- tion. Install in supply line on hot water boilers only. Valve operates through water pressure differentials. It does not require electrical connection.

DRAIN VALVE

Manual valve provides means of draining all water from boiler and system. It is often installed in 3/4” tapping at bottom of end boiler section. Or it can be installed in tee where return line enters boiler.

WATER TEMPERATURE CONTROL

Water temperature limit control in relay is adjustable

and may be set as necessary. It may be set as low as 104°F (40°C), or as high as 220°F (104°C). This depends on type and amount of radiation involved and weather conditions.

CIRCULATING PUMP

Every forced hot-water system requires circulating pump. Separate pump or zone valve is required for each zone, if you have a two or more zone system. Pump must have capacity to provide circulation required by your system. Pump is connected into main just ahead of boiler. It is also wired to electrical system.

VENT DAMPER

This product is automatic, motorized stack damper developed to increase efficiency of heating system by reducing standby losses from heating apparatus and conditioned air space. Damper closes chimney vent when burner is off and fully opens it when combustion is required.

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