Riello 40 Installation, Use And Maintenance Instructions page 38

4.5 AIR PRESSURE SWITCH
The air pressure switch is set after all other adjustments have been made. Begin with the switch at the
lowest setting. With the burner working at the minimum output, adjust the dial clockwise, increasing its
value until the burner shuts down. Now reduce the value by one set point, turning the dial anti-clockwise.
Check for reliable burner operation, if the burner shuts down, reduce the value by a half set point.
Attention:
To comply with the EN 676 standard, the air pressure switch must operate when the CO value exceeds 1%
(10,000 ppm). To check this, insert a combustion analyser in the flue, slowly reduce the burner air setting and
verify that the burner shuts down by the action of the air pressure switch before the CO value exceeds 1%.
4.6 BURNER START-UP CYCLE
Normal
Thermostat
Motor
Ignition transformer
1 st
stage
valve
1 st
stage flame
2 nd
stage valve
2 nd
stage
flame
Lock-out
2s max.
When flame-failure occurs during working, shut down takes place within one second.
4.7 START-UP CYCLE DIAGNOSTICS
During start-up, indication is according to the followin table:
Sequences
Pre-purging
Ignition phase
Operation, flame ok
Operating with weak flame signal.
Electrical supply lower than
Lock-out
Extraneous light
Index: Off
20033980
3s max.
40s 10s
COLOUR CODE TABLE
~
170V
Yellow
Lock-out, due to ignition failure
2s max.
Green Red
8 GB
40s 3s max.
Colour code
D4170