Commissioning
37
Worcester Commercial Boiler Series – 6720814332 (2019/04)
Fig. 72 Combustion check flow chart
8.10
Measure ionisation current
▶ Take the boiler out of operation.
▶ Pull the connector plugs apart.
▶ Connect the multi-meter on both sides of the open plugs (in series).
Fig. 73 Connecting the multi-meter
0010026008-001
Yes
No
Yes
Yes
Set boiler to
minimum rate.
Check all seals around the
burner, internal flue seals,
and case seals.
Rectify where necessary.
Turn off boiler and
call Worcester, Bosch
Group help line.
0330 123 3366
No
Boiler is operating
satisfactorily.
No further action
is required.
No
No
Verify flue integrity
O
2
≥ 20.6%
CO
2
< 0.2%
O
2
≥ 20.6%
CO
2
< 0.2%
No
Yes
Check CO and
combustion ratio
at maximum rate
Check CO and combustion
ratio at minimum rate
CO < 350ppm
CO/CO
2
ratio
< 0.0035
CO < 350ppm
CO/CO
2
ratio
< 0.0035
CO < 350ppm
CO/CO
2
ratio
< 0.0035
Flue integrity test
using analyser
Yes
Set boiler to
maximum rate.
START
HERE
Zero the analyser
in fresh air.
See notice above
Record values.
Do not adjust
the gas valve.
≥
= greater than
or equal to
<
= less than
0010010035-001
1.
2.
