Co And Combustion Checks; Finishing Commissioning - Worcester GREENSTAR 24 Installation, Commissioning And Servicing Instructions

6.9

CO AND COMBUSTION CHECKS

The following combustion and flue integrity checks will be 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 flow chart is given for guidance; the details of the checks are given in
the following sections:
• Checking flue integrity, refer to section 8.2, page 38.
• Setting the air/gas ratio, refer to section 8.5, page 39.
Set boiler to
START HERE
maximum rate.
<
= less than
>
= greater than
or equal to
No
Record values.
Do not adjust
the gas valve.
Turn off boiler and
call Worcester, Bosch
Group help line.
0330 123 3366
Fig. 51 Combustion check flow chart
6.10

FINISHING COMMISSIONING

▶ Check the gas inlet pressure ( page 38).
6 720 811 922 (2014/07)
Zero the
analyser
in fresh air.
See notice
above
O > 20.6%
2
No
CO < 0.2%
2
Yes
CO < 350ppm
CO/CO ratio
2
< 0.004
Yes
No
NOTICE: BEFORE CO AND COMBUSTION CHECKS:
▶ Refer to chapter 8 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 air/gas ratio valve is factory set and must not be
adjusted during commissioning unless this action is
recommended following contact with the Worcester,
Bosch Group help line 0330 123 3366.
Flue integrity test
using analyser
Verify flue integrity
Check all seals
around the burner,
internal flue seals,
and case seals.
Rectify where
necessary.
Check CO and
combustion ratio
at minimum rate
CO < 350ppm
Yes
CO/CO ratio
2
< 0.004
▶ Check that condensate is being discharged from the condensate
hose. If that is not the case, switch the ON/OFF switch off and on
again. That activates the syphon filling function ( page 36). Repeat
the procedure several times until condensate starts running out.
Commissioning
O > 20.6%
2
Yes
CO < 0.2%
2
No
Check CO and
combustion ratio
at maximum rate
CO < 350ppm
No
CO/CO ratio
2
< 0.004
Yes
Set boiler to
minimum rate.
Boiler is operating
satisfactorily.
No further action
is required.
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