BS 5440-1:2023

Chimneys, flue pipes and ventilation for gas appliances of rated input not exceeding 70 kW net (1st, 2nd and 3rd family gases). Design, installation, commissioning and maintenance of chimneys. Specification | Status: Current

1 Scope This part of BS 5440 specifies requirements for the installation of gas appliances to chimneys, chimney installation work likely to be undertaken by gas engineers and operatives working under UK gas industry conditions, and requirements for the maintenance of chimneys. It is applicable to open-flued chimneys for Type B gas appliances and room-sealed chimney configurations for Type C gas appliances, each of rated input not exceeding 70 kW net (see Note 2 and Note 3), burning 1st, 2nd or 3rd family gases. It applies to chimneys of the natural draught or fanned draught type and is applicable to room-sealed chimneys and open-flued chimneys supplied with the appliance as well as to those supplied separately.

NOTE 1 Type B and Type C appliances are explained in Annex A, Table A.1.

This part of BS 5440 complements the requirements for the design, installation and commissioning of chimneys as required in BS EN 15287‑1 and BS EN 15287‑2, and provides extra requirements that are specific to the UK gas industry. This part of BS 5440 specifies the following:

1. a) requirements for the selection of the correct chimney configuration option for gas appliances in the UK;
2. b) requirements for the installation of gas appliances to new chimneys, or chimney configurations;
3. c) requirements for the installation of gas appliances to existing chimneys or chimney configurations;
4. d) requirements for the installation of appliances which carry a CE, UKCA or UKNI mark and for which the manufacturer’s instructions are available to the installer; and
5. e) requirements for the installation of appliances which do not carry a CE, UKCA or UKNI mark and used/second-hand appliances for which the manufacturer’s instructions are available to the installer.

This part of BS 5440 is applicable to:

1. 1) complete chimneys and all chimney components from the appliance connection to the discharge point into outside air;
2. 2) the installation of gas appliances to existing chimneys that were intended originally for appliances burning other fuels;
3. 3) chimneys for residential park homes; and
4. 4) chimneys for hybrid systems incorporating gas appliances.

This part of BS 5440 is not applicable to:

1. i) gas-fired incinerators (see BS 5871‑3 for the installation of decorative fuel effect appliances);
2. ii) leisure accommodation vehicles; or
3. iii) appliances designed for use on 100% hydrogen.

This part of BS 5440 includes compatibility of appliances installed in the UK with new chimneys designated under BS EN 1443 and with existing chimneys, including non-designated chimneys.

NOTE 2 In the case of an individual appliance connected to a chimney, the 70 kW maximum rated input relates to that appliance. In the case of more than one appliance in the same room connected to a single chimney, the 70 kW maximum rated input relates to the sum of the rated inputs of all the appliances. In the case of appliances in separate dwellings connected to a shared flue in a chimney, e.g. an SE-duct or a U-duct, the 70 kW maximum rated input relates to the rated input of each individual appliance.

NOTE 3 Installation of gas-fired hot water boilers having rated inputs exceeding 70 kW is specified in BS 6644 and the Institution of Gas Engineers and Managers Standard IGEM/UP/10.

NOTE 4 The data in this British Standard refers to heat input expressed in terms of net calorific values (CV) with conversion given for natural gas gross CV quoted in brackets where appropriate. The ratio of gross heat input to net heat input is approximately 1.1:1 for natural gas propane and butane. For example, conversion of 11 kW input based on gross CV for natural gas to the equivalent net CV input is as follows:

net input = 11/1.11 = 10 kW.