Technical Booklet L Combustion Appliances and Fuel Storage Systems·Page 26·2.20
Condensates in flues
Flues must control water condensation through insulation (for non-condensing appliances) or by using condensate-resistant components (for condensing appliances). Condensing appliances must have a drain for condensate disposal.
A flue should provide satisfactory control of water condensation. This can be achieved by adopting one of the following provisions –
(a) the flue for a non-condensing combustion appliance should be insulated so that flue gas does not condense during normal operation; or
(b) the flue for a condensing combustion appliance should be lined with components that are impervious to condensates and resistant to corrosion (BS EN 1443 'W' designation) avoiding ledges, crevices, etc.
A condensing combustion appliance should have a suitable drain fitted for the disposal of condensate. Guidance on the disposal of such condensate is given in Technical Booklet N.
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