Listed below are the common Biasi fault codes as described by the boiler manufacturer along with a possible cause.

Biasi Boiler Error Codes Fault Codes

Fault Code	Fault Image	System Behaviour
ER 01 + Reset	N/A	Lack of burner ignition on safety lockout
ER 02 + Reset	N/A	Safety thermostat intervention lockout
ER 03 + Reset	N/A	General lockout
ER 04 +		Faulty primary circuit (no water or absence of flow)
ER 05 +		Faulty fan control system
ER 06 +		Faulty c.h. temp. probe NTC
ER 07 +		Faulty d.h.w. temp. probe NTC
ER 08 +		Faulty external temp. probe NTC
ER 09 +		Faulty flue temp. probe NTC
ER 10 + reset	N/A	Flue probe intervention lockout
N/A		Flame detection error (An flashing + number error flashing
ER 12 +		Faulty central heating temperature probe NTC
ER 13 +		DT Delivery return >40k
ER + 14 + Reset	N/A	Faulty pump or primary temperature above 105°C
ER + 14 + Reset	N/A	Faulty pump or primary temperature above 105°C
ER + 14 +		Absence of flow from temperature gradient (>2K/s)
ER + 19 +		Domestic hot water inlet probe failure (if sent)
ER + 25 + Reset	N/A	Flame detection fault
ER + 69	N/A	Wiring fault lockout
Li	N/A	Primary circuit temp. limit during d.h.w. operation
—	N/A	Boiler Stand-By, hyphens are turned on in sequence to simulate running /antifreeze protection activated)
N/A		Boiler Stand-By, hyphens are turned on in sequence to simulate running /antifreeze protection activated)
N/A		Filling request: The boiler works regularly and the display shows all the icons, but the signal FL is flashing every 1 sec.
N/A		Insufficient pressure: The boiler stops displaying the water lack error.
30c	N/A	Boiler waiting for heat request
N/A		Boiler in summer mode (d.h.w.). The primary circuit temperature is displayed.
N/A		Boiler in winter mode (c.h.+ d.h.w.) The primary circuit temperature is displayed.
N/A		Boiler on demand for d.h.w. power. The d.h.w. temperature is displayed. / Boiler on demand for c.h. power.
N/A		Burner ignition (spark)
N/A		Flame present (Burner on)
N/A		Pre-heating function 3 stars DHW comfort. This information is not displayed. It will be possible to check its state in the section “INFO” value “cF” (the signal “cF” is alternated to the CH temperature value until the end of this function). You can enter the function pushing the buttons 12 and 13 together. The function is confirmed showing ON or OFF alternating for 5 sec. This function is always active at every hour (it’s not possible to set the time slots unless a remote control is connected).
N/A		Pre-heating function 3 stars DHW comfort. This information is not displayed. It will be possible to check its state in the section “INFO” value “cF” (the signal “cF” is alternated to the CH temperature value until the end of this function). You can enter the function pushing the buttons 12 and 13 together. The function is confirmed showing ON or OFF alternating for 5 sec. This function is always active at every hour (it’s not possible to set the time slots unless a remote control is connected).
N/A		Boiler in anti-freeze phase (bP flashing + temperature flashing)
N/A		Boiler in antifrost phase (AF flashing + temperature flashing)
N/A		Set c.h. (all other symbols are disabled)
N/A		Remote control connected – 1 flash every 4 seconds
N/A		Set d.h.w. (all other symbols are disabled)
N/A		Pump activated for the post-circulation phase (Po flashing + temperature flashing)
N/A		Delayed burner ignition for setting the system (uu flashing + temperature flashing)
N/A		Maintenance required The wrench symbol is flashing (without showing any error)
LP	N/A	Boiler in chimney sweep in function. The activation of the chimney sweep occurs configuring the “parameter P09=01” and is visualized: LP= minimum dhw hP= minimum heating cP= maximum heating dP= maximum dhw. The transition occurs with keys 16 (increase) and 15 (decrease) dhw temperature. The writing on the display alternates.
N/A		Boiler in chimney sweep in function. The activation of the chimney sweep occurs configuring the “parameter P09=01” and is visualized: LP= minimum dhw hP= minimum heating cP= maximum heating dP= maximum dhw. The transition occurs with keys 16 (increase) and 15 (decrease) dhw temperature. The writing on the display alternates.