Ignition Gas Pressure Adjustment - Biasi GARDA M90F.24S Service Manual

A short pulse every 4 seconds
1 second ON 1 second OFF
Very fast pulses (4 per second)
Service operation
f
With the boiler switched ON (
re---setting to its original position any of the function se-
lectors 13 (Fig. 28), the Electronic starting control
p.c.b. goes into service operation mode and all the
lamps (14 in Fig. 28) are then activated.
To reset the Electronic starting control p.c.b. to the nor-
mal operation it is necessary to turn the knob
position or switch off the boiler for a short while at
the fused spur isolation switch.
The following table gives the relationship between each
of the possible lamp combinations and their meaning.
Boiler in stand --- by condition.
(function control in
position). position)
Anti--- freeze system active.
Boiler ON condition
(function control in or
position) position)
Faulty boiler or irregular
operation as:
--- Empty primary circuit
--- No primary circuit flow
--- Lack of burner ignition g
--- Excessive temperature in
the primary circuit.
--- Dip --- switch 3 left in the OFF
position
--- Faulty temperature probe
or ), by moving and
to the
Electronic starting control p.c.b.
Normally operating boiler
(see the previous table for details)
C.h. operation
D.h.w. operation
Frost protect operation
D.h.w. operation
Excessive temperature on primary circuit
Faulty c.h. temperature probe NTC
Faulty d.h.w temperature probe NTC
Faulty primary circuit
(no water or absence of flow)
Lack of burner ignition (no ignition signal from
the full seqence ignition device)

Ignition gas pressure adjustment

Minimum gas pressure adjustment
Lack of power supply or fauly electronic
control p.c.b. *
Fauly electronic control p.c.b. *
Lamp Lamp Flashing lamp, alone
OFF ON or simultaneously
with an other lamp.
* These conditions are normal only for a short time when the
power supply is applied to the boiler.
If permanent they indicate a faulty p.c.b.
9.5 Dip---switch selectors
The function selectors 13 (Fig. 28 and Fig. 31) are
microswitches with which it is possible to select the vari-
ous boiler control function modes.
In Fig. 31 the selectors are illustrated in the configur-
ation in which the boiler is set in the factory (natural gas
boiler).
Minimum gas pressure adjustment
Gas conversion
Ignition gas pressure adjustment
Reignition frequency
ON (1)
1 2 3 4
OFF (0)
13
Fig. 31
Selector 1
f
This forces the boiler to operate at the minimum gas
pressure in order to allow the adjustment of the mini-
mum gas pressure at the burner (on the modulation op-
erator of the gas valve).
Flashing lamp,
alternate with
another lamp.
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