Charnwood Country 8B installation instructions Central Heating System, Cold Water Tank

Feed and Expansion Tank	22mm Open Vents
	Cold Water Tank

Overflow			Overflow
			Domestic Hot Water Draw Off
Gravity Radiator
	Gravity Return 28mm	Gravity Flow 28mm	Drain Cock
			Indirect Hot Water Cylinder
			High Limit Thermostat
Low Limit			Central Heating Flow
Thermostat			Circulating Pump

Central Heating Return

Drain Cock at Lowest Point

Fig. 4. Typical Central Heating & Hot Water System

Using 4 Boiler Tappings

22mm Open Vents

inches) each side and 300mm (12 inches) above the appliance should give sufficient air circulation. If a wooden mantelpiece or beam is used in the fireplace it should be a minimum of 460mm (18 inches), and preferably 600mm (24 inches) from the appliance. In some situations it may be necessary to shield the beam or mantelpiece to protect it.

CENTRAL HEATING

SYSTEM

The central heating system must comply with BS:5449 part 1.

If the system is to be a combined heating and domestic hot water system then a double feed indirect hot water storage cylinder to BS:1556 part 1 should be used. In order to prevent the build up of scale and corrosion a suitable inhibitor should

Feed and Expansion Tank

Overflow
Gravity Radiator	Return 28mm	Flow 28mm
Low Limit Thermostat	Gravity	Gravity
Circulating Pump
Central Heating Return
Drain Cock at Lowest Point

Cold Water Tank

Overflow

Domestic Hot Water Draw Off

Drain Cock

Indirect Hot Water Cylinder

High Limit Thermostat

Central Heating Flow

be used. The system must be correctly vented as shown in Figs. 4 and 5. The height differential between the header tank and the appliance must not exceed 15.2 metres (50 feet).

If all four boiler tappings are used then, if possible, diagonal pairs should be connected for domestic hot water and central heating. Where a common return is used an injector tee must be incorporated into the system as shown in Fig. 6. This will ensure that a good domestic hot water supply is maintained when the central heating pump is operating.

The system must incorporate a gravity circuit which will normally

Injector Tee

Fig. 5. Typical Central Heating & Hot Water System

Using 3 Tappings

Gravity Return

(28mm Pipe)

Central Heating Return	Common Return to Boiler
	(28mm Pipe)

Fig. 6. Injector Tee.

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heat the domestic hot water and an unvalved radiator with an output of at least 1 kW. When the appliance is not connected to a domestic hot water system the unvalved radiator(s) on the gravity circuit must have an output of at least 1.25 kW. This is to prevent boiling in case of pump failure. All pipework in the primary circuit must be 28 mm diameter and the gravity flow pipe must rise continuously from the boiler to the open vent. Two typical systems are shown in Figures 4. and 5.

Country 8B WB 10/00