Thermal Control In The; Mode - Biasi GARDA M90F.24S Service Manual

9.12

Thermal control in the "

Circulator on
Is domestic
hot water outlet temperature
YES
lower than that
required?
NO
end of ignition
NO
period?
YES
Fig. 40

" mode

Switch in the function mode
YES water from the domestic hot
NO
YES
NO
NO
NO
Air pressure switch at
work?
NO
YES interrupts ignition discharges
turns on lock--- out light
NO
YES
Air pressure switch at
work?
Taking
water circuit?
lock memorised? NO
Air pressure switch at
rest?
Air pressure switch at
work?
presence of flame? YES
starts ignition discharges
opens gas valve
beginning of ignition period
flame presence? YES
closes gas valve
stops fan
memorizes lock
reset push--- button
pressed?
flame presence? NO
Safety thermostat
NO
opens the circuit?
NO
Electronic starting control p.c.b.
Circulator off
NO
Ignition device off
Ignition device off
cancels lock
YES
starts fan
YES
beginning of wait period
YES
interrupts ignition discharges
gas valve open
YES
YES
closes gas valve
21