Compartment installation

Compartment clearances

Follow the requirements of BS5410 and note:

• Minimum clearances must be maintained.
• An access door is required to install, service and maintain the boiler and any ancillary equipment.
• If fitting the boiler into an airing cupboard use a non-combustible, perforated material (maximum hole sizes of 13mm) to separate the boiler from the airing space.

Venting compartments

• Ventilation must be provided for boilers fitted into compartments as described in BS5410.
• A minimum of 2 air vents must be fitted, one at low level (C) and another at high level (D) onto the same wall using the same air (E) for circulation.
• Free air must not be taken from a room or internal space containing a bath or shower and must not communicate with a protected area such as a hall, stairway, landing, corridor, lobby, shaft etc.
• Air vents must allow access for clean free air and must be sited to comply with the flue terminal position requirements.
• Air ducting runs must not exceed 3m.
• Low level air vents must be less than 450mm from the floor.
• A warning label must be added to the vents with a statement to the effect: “Do not block this vent. Do not use for storage”.

Air supply - CF (conventional flue)

An adequate supply of free air must be delivered to the boiler for combustion purposes through a permanent inlet, such as an air brick, into the area where the boiler is situated.

*Due to changes in BS 5410 and modern building design these figures no longer incorporate the adventitious ventilation allowance.

Conventional flue

Room sealed flue