Commissioning
Worcester Commercial Boiler Series – 6720814332 (2019/04)
36
8.9
Measure the CO and CO
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content
Assuming combustion with excess air, the CO content of the flue gas
must be less than 350 ppm, or 0.035 % by volume. If the CO content is
roughly 350 ppm or higher, the cause, which is most likely to be related
to soiling of the burner, a defect in the burner or recirculation of the flue
gases, must be found.
▶ Take the boiler out of operation.
▶ Remove the cap of the flue gas testing point [1].
Fig. 71 Removing the cap of the flue gas testing point
[1]
Flue gas testing point
[2]
Air supply testing point
▶ Connect the flue gas analyser to the test point.
▶ Bring the boiler into operation.
▶ Make sure that the boiler can dissipate the heat generated.
▶ Start the chimney sweep mode (
Chapter 7.3).
▶ Switch off the chimney sweep mode.
▶ Take the boiler out of operation.
▶ Remove the flue gas analyser.
▶ Mount the cap of the flue gas testing point.
▶ Bring the boiler into operation.
8.9.1
CO and combustion checks
The following combustion and flue integrity checks are mandatory from
April 2014 and these values must be recorded on the Benchmark check
list, at the back of this manual.
Once the gas rate and pressure have been confirmed as acceptable then
the CO and combustion checks can be undertaken.
The boiler case must be fitted whilst these checks are carried out.
NOTICE:
BEFORE CO AND COMBUSTION CHECKS:
▶ Refer to section 5.2 and section 8.7 a to verify gas type, gas inlet
pressure, and gas rate.
Visually check the integrity of the whole flue system and confirm that
all the components are correctly assembled, fixed and supported.
▶ The flue gas analyser must be the correct type as specified in
BS 7967.
Before use the analyser must have been calibrated as specified by the
manufacturer.
The installer must be competent in the use of the analyser.
Check and zero the analyser in fresh air as specified by the
manufacturer.
▶ The gas valve is factory set and must not be adjusted during
commissioning if found to be out of tolerance, please contact the
Worcester, Bosch Group help line 0330 123 3366.
0010010034-001
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