BS 4876:1984

Foreword
Committees responsible
Specification
Section one. General
1.1 Scope
1.2 Definitions
1.3 Marking
1.4 Test fuels
1.5 Classification of heating appliances
Section two. Performance requirements
2.0 General
2.1 Class 1: appliances employing natural draught
      vaporizing burners
2.2 Class 2: appliances employing high/low forced
      draught vaporizing burners
2.3 Class 3: appliances employing on/off forced
      draught vaporizing burners
2.4 Class 4: appliances employing rotary vaporizing
      burners
2.5 Class 5: appliances employing on/off pressure
      jet burners
Section 3. Test procedures
3.1 Test procedure 1: primary screening
3.2 Test procedure 2: efficiency of boilers
3.3 Test procedure 3: overall efficiency of indirect
      impelled convection air heaters
3.4 Test procedure 4: overall efficiency of direct
      impelled convection air heaters
3.5 Test procedure 5: efficiency of direct natural
      convection air heaters
3.6 Test procedure 6: sensitivity to flue conditions
      (appliances with integral draught diverter)
3.7 Test procedure 7: sensitivity to flue conditions
      (appliances without integral draught diverter)
3.8 Test procedure 8: response to load change
      (manually controlled appliances)
3.9 Test procedure 9: response to load change (semi-
      automatic appliances)
3.10 Test procedure 10: start and shut-down combustion
      performance
3.11 Test procedure 11: hearth and side panel
      temperatures
3.12 Test procedure 12: fuel flooding test
3.13 Test procedure 13: effects of voltage variation
3.14 Test procedure 14: electrical safety
3.15 Test procedure 15: boiler reliability and
      endurance: on/off appliances
3.16 Test procedure 16: boiler reliability and
      endurance: high/low appliances
3.17 Test procedure 17: reliability and endurance:
      manually controlled natural convection air
      heaters
3.18 Test procedure 18: reliability and endurance:
      automatic and semi-automatic air heaters
3.19 Test procedure 19: sensitivity to wind of an
      appliance designed to operate with its own
      integral flue arrangement
Section four. Measurement methods
4.1 Method 1: determination of smoke number and smoke
      index
4.2 Method 2: determination of flue gas composition
4.3 Method 3: determination of flue gas temperatures
4.4 Method 4: determination of flue draught
4.5 Method 5: degree of incomplete combustion,
      determination of combustible gas index
4.6 Method 6: determination of gas velocity by pitot
      tube
4.7 Method 7: determination of fuel flow rate
4.8 Method 8: determination of surface temperatures
      and effectiveness of guards
4.9 Method 9: determination of float control
      temperatures
4.10 Method 10: determination of exhaust gas heat
      (stack) losses
Appendices
A. Suggested forms for use by laboratory staff during
    a preliminary inspection of an appliance
B. Suggested report forms
C. Typical points for examination after endurance test
Tables
1. Test fuel requirements
2. Summary of test procedures and measurement methods
3. Report for test procedure 13
4. Creepage distances and clearances
5. Report for test procedure 15
6. Report for test procedure 16
7. Programme of tests and adjustments for test
    procedure 17
8. Report for test procedure 17
9. Report for test procedure 18: automatic appliances
10. Report for test procedure 18: semi-automatic
    appliances
Figures
1. Circuit example, class 3 and 4 appliances
2. Circuit example, class 5 appliance with photo-
    electric cell
3. Test rigs for hot water boilers operating below
    a temperature of 100 deg C
4. Thermometer pocket
5. Water collecting method
6. Resistance grid
7. Air flow
8. Test layout
9. Air flow
10. Orifice plate
11. Sensitivity to flue conditions: flue duct system
12. Sensitivity to flue conditions: flue duct system
13. Standard test hearth
14. Side panel temperature measuring boards
15. Total of four boards assembled to measure boiler
    side panel temperatures
16. Brick central test chamber
17. Reliability and endurance test: water system
18. Horizontal discharge, with integral flue arrangement
19. Suction pyrometer
20. Basic gas and signal circuits
21. Appliance limits on a typical curve shape
22. Use of pitot tube
23. Fuel measurement system
24. Contact thermocouple
25. Test probe
26. Determination of exhaust gas heat losses applicable
    to standard test fuels

Specifies the performance requirements and methods of testing for flued oil burning appliances (e.g. boilers and air heaters), up to and including 44 kW capacity, used for hot water supply and for space heating purposes.