Re-Assembly Of The Burner Cover; Setting The Air/Gas Ratio - Worcester Greenstar Highflow 440CDi ERP Installation, Commissioning And Servicing Instructions

SERVICING AND SPARES
▶ Pour water into the top of the heat exchanger to flush out the debris.
Fig. 55
▶ Refit the cleaning access cover assembly in reverse order, the metal
plate [3] first, then the new seal [2], lastly the access cover [1].
▶ Refit the condensate trap.
▶ Pour 250ml of clean water into the heat exchanger to fill the
condensate trap.
▶ Hand tighten the bolts and then use a spanner to tighten the bolts a
further half turn.
3
2
Fig. 56
36
6.7.5
▶ Refer to figure 48 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
▶ Using a 10mm spanner, tighten the two castellated nuts [2a] until
▶ Using a 13mm spanner tighten the rear nut [4a]until the burner
▶ 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
▶ Insert the clips [1] and secure.
▶ After re-assembly check that the CO/CO
6720818079-21.1Wo
6.8
1
To set the maximum CO
▶ To adjust the CO
▶ Press and hold down the Service engineer button [1] for 10 seconds
▶ Turn temperature control [2] to maximum, the boiler will then go to
▶ Remove the combustion chamber cover
6720818079-22.1Wo
▶ Remove plastic cap and using a flat bladed screwdriver
▶ Set the maximum CO
▶ Replace the combustion chamber cover
▶ Check the maximum CO
▶ Check the CO is less than 200ppm

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.
to figure 48, on to the studs [2] to secure the burner cover to the heat
exchanger.
the burner cover bottoms out on the heat exchanger.
cover bottoms out on the heat exchanger.
visible.
the section "Setting the air/gas ratio" on page 36.

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.
:
2
it will be necessary to first operate the boiler at
2
maximum output
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.
(+ or -) using the adjuster [3]
2
referring to table 15
2
CO should be measured 10 minutes after firing the
2
boiler
Greenstar Highflow CDi
levels are as described in
2
ErP - 6720818077 (2016/04)