Giatsu WD2N8B Serie Manuel De L'utilisateur Et D'installation page 113

Symptom 6: Space heating capacity shortage at low outdoor temperatures
POSSIBLE CAUSES
Backup heater operation
is not activated.
CORRECTIVE ACTION
• Check if that the "OTHER HEATING SOURCE/ IBH FUNCTION" is
enabled.
• Check whether or not the thermal protector of the backup heater has been
activated.
• Check if booster heater is running, the backup heater and booster heater
can't operate simultaneously.
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