BURNER DESCRIPTION (A)
1 Combustion head
2 Ignition electrode
3 Screw for combustion head adjustment
4 Sleeve
5 Minimum air pressure switch
(differential operating type)
6 Flame sensor probe
7 Air pressure test point
8 Gas pressure test point and head fixing
screw
9 Screws securing fan to sleeve
10 Slide bars for opening the burner and
inspecting the combustion head
11 Servomotor controlling the gas butterfly valve
and of air gate valve (by means of a variable
profile cam mechanism).
When the burner is not operating the air gate
valve is fully closed in order to reduce heat
dispersion from the boiler due to the flue
draught which draws air from the fan suction
inlet.
12 Plate with four hole knock-outs for electrical
cable routing
13 Air inlet to fan
14 Gas input pipework
15 Gas butterfly valve
16 Boiler mounting flange
17 Flame stability disk
18 Flame inspection window
19 Plug-socket on ionisation probe cable
20 Motor contactor and thermal cut-out reset
button
21 Air gate valve
22 Control box with lock-out pilot light and lock out reset button
23 Two switches:
- one "burner off - on"
- one for "1st - 2nd stage operation"
24 Plugs for electrical connections
Two types of burner failure may occur:
• Control box lock-out: if the control box
22)(A) pushbutton (red led) lights up, it indi cates that the burner is in lock-out.
To reset, hold the pushbutton down for
between 1 and 3 seconds.
• Motor trip: release by pressing the pushbut ton on thermal cutout 20)(A).
Audited Supplier 
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