Worcester Bosch Commercial Worcester GB162 commercial boiler (GB162-50, GB162-65, GB162-80, GB162-100)
Heat only, commercial, natural gas and LPG (after conversion)
Combustion figures
| Figure | Natural gas (G20) | LPG (G31) |
|---|---|---|
CO₂ at high rate More infoHide infoFrom Table 25 (MI 15 Technical specifications): CO₂ content at full load, natural gas G20. No tolerance or measuring conditions are given with it. The MI prints two figures separated by a slash for the GB162-50 and GB162-65 and doesn’t say what they mean. There is no CO₂ target in the commissioning or inspection checks: MI 10.2.9 is headed Measuring the flue gases CO₂ emissions but only gives a CO limit, and the service record log book (MI 13.5, Table 21) has spaces to record CO₂ at full load and part load without target figures. The MI says to adjust the gas/air ratio only at part load and only by the gas/air pressure differential, never by flue gas values such as CO/CO₂/NOx (MI 10.2.7). No LPG CO₂ figure is given. Full load is set with the flue gas test (MI 9.2, Table 10). |
| Not given in MI |
CO₂ at low rate More infoHide infoThe MI gives no CO₂ figure at part load for either gas. The service record log book (MI 13.5, Table 21) has a space to record CO₂ content at part load but no target figure. | Not given in MI | Not given in MI |
Maximum CO More infoHide infoFrom MI 10.2.9: CO in air-free condition, measured at the flue gas measuring point (the left-hand measuring point) with the boiler at full load in flue gas test mode, one minute after the Burner LED lights, with at least 2 thermostatic radiator valves open. Values of 400 ppm or more indicate an incorrect burner adjustment (MI 10.2.7), a dirty gas burner or heat exchanger or burner faults, and the cause must be found and removed. The MI gives one limit and doesn’t say it is for one gas only. The inspection check (MI 12.9) refers back to MI 10.2.9. | less than 400 ppm or 0.04 vol. % (air-free) | less than 400 ppm or 0.04 vol. % (air-free) |
CO/CO₂ ratio More infoHide infoThe MI gives no CO/CO₂ ratio. The CO check in MI 10.2.9 is an air-free CO figure only. | Not given in MI | Not given in MI |
O₂ | Not given in MI | Not given in MI |
Working inlet pressure More infoHide infoFrom MI 10.2.6, measured at the testing nipple for the gas hook-up pressure on the gas valve inside the boiler (Fig. 85), with the boiler at full load in flue gas test mode, one minute after the Burner LED lights, and at least 2 thermostatic radiator valves open. If the required pressure isn’t available, check the gas supply pipe or contact the gas utility company; if it is too high, a gas pressure regulator must be fitted upstream of the gas fitting. Table 28 (MI 15) gives the gas category as GB/IE II2H3P 20; 37 mbar. The boiler is delivered set for natural gas H and can run on LPG 3P (G31) after adaptation by a Gas Safe registered installer (MI 10.2.5, Table 15). Table 28 lists natural gas H (G20) and LPG 3P (G31) against GB162-65/80/100 only, but Tables 14 and 25 give an LPG injector size for the GB162-50 as well; the MI doesn’t explain the difference. MI 12.6 (inspection) refers back to MI 10.2.6. |
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From 6720813171 (2015/04)
Enter service mode for high and low rate
High rate
- Hold Chimney sweep for more than 2 but no more than 5 seconds, until a steady dot shows bottom right of the display. It runs at maximum.
- Hold Chimney sweep and Service (spanner) together for more than 2 seconds. Display shows L-- (100%).
Low rate
- Hold Reset until the display shows L25 (80 kW), L20 (65 and 100 kW) or L30 (50 kW) for minimum.
- Hold Chimney sweep for more than 2 seconds until the dot goes. It also ends by itself after 30 minutes or if the power is cut.
Models
| Model | Gas |
|---|---|
| GB162-50 | NG |
| GB162-65 | NG |
| GB162-80 | NG |
| GB162-100 | NG |
Source: Worcester Commercial Boiler Series GB162-50/65/80/100 wall hung gas fired condensing boiler installation and servicing instructions, 6720813171 (2015/04).
Sections: Cover (no GC numbers); 2 General; 8.5.1 Electrical wiring diagram (Fig. 37 footnote naming Logamax plus GB162-50/65); 9.2 BC10 control operating instructions (Table 10 Flue gas test, Table 11 Service mode); 10.2.5 Checking the appliance configuration (Tables 14 and 15); 10.2.6 Measuring the gas inlet pressure (working pressure); 10.2.7 Checking and adjusting the gas/air-ratio; 10.2.9 Measuring the flue gases CO₂ emissions; 12.6 and 12.9 Inspection; 13.5 Service record log book (Table 21); 15 Technical specifications (Tables 25 and 28).
Spotted something wrong? Tell us.
Check these figures against the MI for the appliance in front of you, matched by GC number and manual date. Combustion work needs a calibrated analyser and a Gas Safe registered engineer.