Re-Assembly Of The Burner Cover; Setting The Air/Gas Ratio - Worcester Greenstar FS 30CDi Installation, Commissioning And Servicing Instructions

SERVICING AND SPARES
Hand tighten the bolts and then use a spanner to tighten the bolts a
further half turn.
3
2
Fig. 53
6.7.5

Re-assembly of the burner cover

NOTICE: Burner gasket seal
Always replace the burner seal with a new one when
the joint has been disturbed.
Refer to figure 45 and re-assemble the burner in reverse order
Fit a new burner gasket seal [8].
Refit the burner.
Insert the burner cover under the rear nut [4a] and hand tighten.
Assemble the washers/ spring [2b], and castellated nuts [2a], refer
to figure 45, on to the studs [2] to secure the burner cover to the heat
exchanger.
Using a 10mm spanner, tighten the two castellated nuts [2a] until
the burner cover bottoms out on the heat exchanger.
Using a 13mm spanner tighten the rear nut [4a]until the burner
cover bottoms out on the heat exchanger.
The nuts will stop turning at this point, do not overtighten.
If necessary, back the nuts off slightly until the hole for the clip [1] is
visible.
Insert the clips [1] and secure.
After re-assembly check that the CO/CO
the section "Setting the air/gas ratio" on page 34.
34
1
6720818079-22.1Wo
levels are as described in
2
6.8

Setting the air/gas ratio

NOTICE: SETTING THE AIR/GAS RATIO
The air/gas ratio is factory set and should not
normally need adjustment
Only adjust if the values are still out of range when all
other possible causes have been checked
NOTICE: COMBUSTION TESTING
The setting of the air/gas ratio must be carried out by
a competent registered gas engineer, such as a Gas
Safe registered engineer or British Gas engineer.
Setting of the air/gas ratio must not be attempted
unless the person carrying out the test is equipped
with a combustion analyser conforming to BS 7927
and is competent in its use.
All CO/CO readings must be taken with the combustion
2
chamber cover ON.
Adjustments can only be made with the cover off.
To set the maximum CO :
2
To adjust the CO it will be necessary to first operate the boiler at
2
maximum output
Press and hold down the Service engineer button [1] for 10 seconds
Turn temperature control [2] to maximum, the boiler will then go to
maximum output
The control will resume normal operation after 15
minutes or if the Service engineer button [1] is pressed
for more than one second.
Remove the combustion chamber cover
Remove plastic cap and using a flat bladed screwdriver
Set the maximum CO (+ or - ) using the adjuster [3]
2
Replace the combustion chamber cover
Check the maximum CO referring to table 13
2
CO should be measured 10 minutes after firing the
2
boiler
Check the CO is less than 200ppm
If further adjustment is required, remove the combustion chamber
cover and set adjuster [3] as necessary
Replace the cover and check the maximum CO
Max mode
Service
mode
1
Min mode
≈
10 s 10 s
Fig. 54 Setting air/gas ratio
Greenstar FS CDi
again
2
Max adjustment
3
2
Min adjustment
4
2
ErP
6720818079 (2016/04)