Glow-worm Hideaway 40BF - Manual (Page 8)

8 221691B
Diagram 2.2
FULLY PUMPED SYSTEM
(DIAGRAMMATIC)
2 Water Systems
0870
1 metre
MIN.
27metres
MAX.
PUMP
To Heating
Circuit
TO INDIRECT
CYLINDER
22mm VENT
15mm
COLD FEED
Distributor tube in
pumped return
connection
BOILER
CL
DRAIN OFF
COCK
PRESSURE LOSS OF BOILER Diagram 2.3
0872
600
500
400
300
200
100
0
12
8
4
0
0 4 8 12 16 20 24 28
FLOW RATE (LITRES/MINUTE)
WATER PRESSURE LOSS (mm HEAD OF WATER) WATER PRESSURE LOSS (INCHES HEAD OF WATER)
24
16
800 32
28
20
700
0 1 2 3 4 5 6
FLOW RATE (GALLON/MINUTE)
2.3 Gravity Domestic and Pumped Heating
It is recommended that a cylinder thermostat is used to prevent
the stored water temperature becoming unnecessarily high
when the central heating pump is off.
The domestic primary flow and return must be 28mm o.d. The
installation must comply with the current issue of BS5546 and
BS6700, see diagram 2.1.
If the above conditions cannot be met, it is suggested that a fully
pumped system be used.
2.4 Pumped Heating and Hot Water
Where a single flow and return is taken from the boiler, a
minimum static head of 1metre (3ft3in) must be provided
between the water line of the feed tank and the centre of the
waterway, see diagram 2.2.
2.5 Circulation Pump
Normally the pump should be set to give a temperature difference
of 11
o C (20 o F) across the boiler. At the appropriate pumped flow
rate the pressure loss through the boiler can be found from the
graph, diagram 2.3.
Use a pump with integral valves or fit isolating valves as close
to the pump as possible.
Note: If the pump is to be fitted inside the boiler casing a heat
shield kit is required. Kit No. 425837.
2.6. Cylinder
For all systems supplying domestic hot water the cylinder must
be indirect.
2.7 Safety Valve
A safety valve need not be fitted to an open vented system.
2.8 Draining Tap
A draining tap must be provided at the lowest points of the
system which will allow the draining of the entire system,
including the boiler and hot water cylinder.
Draining taps should be to the current issue of BS2879.
3 Flue and Ventilation
3.1 Flue
Detailed recommendations for flues are given in the current
issue of BS5440 Part 1.
The boiler must be installed so that the flue terminal is exposed
to the external air. It is important that the position allows the free
flow of air across it at all times.
3.2 Terminal Positioning
The minimum acceptable spacings for the terminal to
obstructions, other terminals and ventilation openings are given
in diagram 3.1.
Car port or similar extensions of a roof only, or roof and one wall,
require special consideration with respect to openings, doors
and windows under the roof. Care is required in protecting the
roof if made from plastic sheeting. Seek further advice if the car
port consists of a roof and two or more walls from the local gas
undertaking.
Where the terminal is within 850mm (34in) below plastic guttering,
an aluminium shield 1.5metres (5ft) long should be fitted to the
underside and immediately beneath the guttering.
The air inlet and products outlet duct and the terminal of the
boiler must not be closer than 25mm (1in) to combustible
material.
3.3 Timber Frame Building
If the boiler is to be installed in a timber frame building it should
be fitted in accordance with the Institute of Gas Engineers
document IGE/UP/7/1998. If in doubt seek advice from the local
gas undertaking or Hepworth Heating Ltd.