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42
AST 14 C 258/00
In case of flame shutdown a post-circulation is carried out according to the operation
request (30 sec. in DHW mode; P13 in heating mode with three-way valve in the relevant
operation position) and a 10 second post-ventilation to clean the chamber at the ignition
speed (P6) + 900 rpm.
To resume the shutdown condition it is necessary to wait 5 seconds and press the “reset”
key, or use the remote control. In the latter case maximum three (3) consecutive reset
attempts are allowed within 24 hours. Then it will be necessary to reset the alarms directly
on the boiler.
Hereinafter is boiler operation logical diagram:
Ventilatore di combustione
ON/OFF
Elettrovalvola
Pressostato aria
Termostato fumi
Accensione
Rilevazione
Blocco
Tempo verifica pressostato aria
o termostato fumi
TW tempo di attesa
Accensione
del bruciatore
Bruciatore acceso
funzionamento normale
Tempo di sicurezza Ts
Blocco
Funzioni
Tempi
The flame control switches to shutdown status if the flue gas probe and thermostat do not
give the consensus necessary for a correct operation (see page 56/57).
DHW PRIORITY
With boiler running in “DHW” or “DHW + CH” mode, DHW priority flow switch electric
contact closing will originate a DHW operation request, thus starting DHW modulation.
The operation request in DHW mode has the priority on all other requests, and finishes
when the previously mentioned electric contacts are open again.
WARNING: With parameter P15, it is possible to delay the flow switch reading for
the DHW mode (from 0 to 3 seconds).
