15
20079566
GB
Installation
5.8
Burner operation
5.8.1
Adjustments prior to ignition
The following adjustments must be carried out:
–
open the manual valves upline of the gas train;
–
bleed the air from the gas pipes using the screw on the socket
(Fig. 13 on page 14).
5.8.2
Burner start-up
Close the thermostat and switch on the burner's power. The burn-
er starts up in pre-purging mode at maximum speed. Subse-
quently, the START value speed decreases and start-up occurs.
If the fan starts up but at the end of the safety time the flame does
not appear, burner goes into lockout mode. Reset and wait for a
new start-up attempt. If ignition continues to not occur, it may be
the case that the gas is not arriving at the combustion head within
the safety time of 3s.
Rotate the screw V1, located on the gas valve mixer, slightly in an
anti-clockwise direction (Fig. 15).
Once the burner has fired, proceed with the global adjustment of
the burner.
5.8.3
Fan adjustment
Modulation is based on variable-speed technology. Combustion
air delivery can be adjusted by varying the motor's speed (rpm).
The proportioning gas train delivers the right amount of fuel, de-
pending on the pressure detected in the purging circuit. Hence
the output delivered is adjusted by varying the motor's speed of
rotation. The speed of the motor can be adjusted by means of
three “Trimmers” (Fig. 15).
5.8.4
Gas valve adjustment
The adjustment of the output of gas is achieved by using the two
screws V1 and V2.
To alter the maximum output of gas use screw V1:
–
To increase the output: turn the screw clockwise (tighten);
–
to reduce the output: turn the screw anticlockwise (unscrew).
To alter the minimum output of gas act on the screw V2 on the
gas valve.
Turn the screw with a tool:
–
To increase the output: turn the screw clockwise (tighten);
–
To reduce the output: turn the screw anticlockwise (unscrew).
Definition of the adjustments for the fan.
The adjustments are carried out by means on three potentiome-
ters on board of the motor control box
START
determines the air in the start phase
MIN
determines the minimum modulation
MAX
determines the maximum modulation
Reset button
Maximum output
Start
Minimum output
20079520
Fig. 15
Gas valve
20076453
Fig. 15
Maximum flow adjustment (V1)
Minimum gas flow
adjustment (V2)
+
-
+
-
