Glow-worm 56/3 Back Boiler - Manual (Page 8)

8 221724B
3 Flue and Ventilation
If a flue and false chimney breast are to be constructed all
openings for pipework to upper floors etc., must be sealed.
The only opening for the back boiler must be at the front,
being of the dimensions as shown in diagram 1.2.
If a specially built compartment is constructed for the back
boiler, it must conform to the requirements of the current
issue of BS5440 Part 1 and BS5871.
The flue should, preferably, end above ridge height but at
least above the eaves of a pitched roof. Use a certificated
terminal.
3.4 Ventilation - Back Boiler and Fire Front
It is important that the room in which the back boiler unit is
installed has adequate air inlets to ensure correct operation
as specified in the current issue of BS5440 Part 2.
Ventilation requirement for this back boiler is:
87cm 2 (13.5in 2 )
This ventilation area takes into account the total requirement
of the back boiler unit and any of the specially designed gas
fire fronts.
The ventilation openings may communicate direct with
outside air or with an internal room or space (such as a hall)
which itself is provided with a permanent air vent of the same
effective area. The permanent air vent should be in a
position which minimizes nuisance to occupants due to
draughts.
This vent must NOT be placed in the builder’s opening.
If the appliance is to be installed in a room already containing
another fuel burning unit, the air supply required for this other
unit MUST be added to the figure above.
Any air vent taken through a cavity wall must be ducted.
3.5 Extract Fans
If an extract fan is fitted in the premises, there is a possibility
that if adequate air inlet openings are not provided spillage of
the products of combustion could occur.
When openings are fitted in accordance with the
recommendations of the current issue of BS5440 Part 2,
extract fans should not cause spillage.
Where such a fan installation is found, a clearance of
products test must be conducted as described in the fire front
Installation Instructions.
This test must be carried out with the back boiler fitted with
its fire front.
See also Section 6.3 of these instructions.