Glow-worm 24ci - Page 14

14
4000123942-2
Control
valve
Flow
Drain
point
Bypass
valve
Domestic
water
Heating
circuit
Return
Additional
expansion
vessel
(if required)
Hot water out
Cold supply in
Drain
point
Boiler
Filling device
9898
Additional
Bypass valve
(if required)
*
*
Control
valve
Flow
Drain
point
Bypass
valve
Heating
circuit
Return
Additional
expansion
vessel
(if required)
Boiler
Diagram 3.2
10157
24ci
18si
'A'
Additional
Bypass valve
(if required)
*
*
'A'
TEMPORARY
CONNECTION
HOSE
UNION
HOSE
UNION
SUPPLY
PIPE
CONTROL
VALVE
CONTROL
VALVE
DOUBLE
CHECK
VALVE
BOILER
RETURNFLOW
HEATING
CIRCUIT
DRAIN
POINT
SUPPLY
PIPE
AIR GAP
TUNDISH
CONTROL
VALVE
CONTROL
VALVE
TYPE CA BACKFLOW
PREVENTION DEVICE
BOILER
RETURNFLOW
HEATING
CIRCUIT
DRAIN
POINT
Method 1
Method 2
Diagram 3.3
11593
3.1 Bypass
• The boiler is fitted with an adjustable automatic bypass.
Ensure that under no circumstances does the flow rate drop
below the figure specified, see table 1.
• A system bypass is not required on the central heating circuit
unless the system controls will not ensure a minimum water
flow rate.
• Where a bypass has to be fitted, the bypass must be placed
at least 1.5 metres away from the appliance, see diagram 3.2.
3.2 Filling the system 24ci.
• An integral filling device is fitted to the boiler to initially fill the
system and replace water lost during servicing, see the relevant
parts of diagram 2 controls and lighting and diagram 1.
3 Heating System Design
TABLE 1. FLOW RATE
Model Minimum flow rate
This is equal to 20°C differential at maximum
heat input.
24ci 16.94 litres per minute
18si 13.21 litres per minute
3.3 Filling the system 18si.
• Provision for filling the system must be made. The methods
are shown in diagram 3.3. There must be no permanent
connection to the mains water supply, even through a non-
return valve.
NOTE: It is important that fittings used for connection to
potable water comply with the water undertakings requirements.