Biasi Riva Advance M96.24SM Fault codes & diagnostics

37 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.

Combi Natural Gas 24 kW Discontinued

This boiler uses LED flash patterns

Count the flashes in one repeating group before the pause. That number is your fault code. Do not reset until you have noted it. How to read fault codes →

Severity at a glance

Each cell = one fault code. Hover to identify.
33 High 4 Low
Just want the most common Biasi Riva Advance M96.24SM faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 37 documented codes

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LED / flash-pattern codes
Lamps flashing

Your boiler is operating normally under a central heating demand and is simply showing its current status rather than a fault.

Low DIY-safe £0

What to check first

  1. Check your thermostat or programmer settings to confirm if you want the heating on
  2. Turn down the thermostat if you wish the heating to stop
  3. Monitor the lights to see if they change pattern once the heating demand is met
Full explanation for Lamps flashing
Lock-out signal lamp D blinks

Your boiler is notifying you that a change in its internal settings was detected and needs to be saved by a qualified technician.

Low Engineer only £80-130

Parts commonly replaced

  • Main Printed Circuit Board (PCB)
Full explanation for Lock-out signal lamp D blinks
Digital codes
1 second ON 1 second OFF

Your boiler is operating normally and is currently running because there is a demand for heating or hot water.

Low DIY-safe £0

What to check first

  1. No action is required as this light sequence indicates normal operation.
  2. Check your thermostat or hot water tap to confirm you intended for the boiler to be running.
Full explanation for 1 second ON 1 second OFF
30c

Your boiler has detected that the water temperature has risen too high, causing it to shut down for safety.

High Engineer only £120-280

Parts commonly replaced

  • Overheat Thermostat
  • Circulation Pump
  • Main Heat Exchanger
Full explanation for 30c
A short pulse every 4 seconds

Your boiler is working correctly and is simply in standby mode while its built-in protection prevents the internal pipes from freezing.

Low DIY-safe £0

What to check first

  1. No action is required as this is a normal status message.
  2. Ensure your gas and electricity supplies are left on during cold weather.
  3. The light will stop pulsing once the boiler temperature rises or you turn on your heating.
Full explanation for A short pulse every 4 seconds
E01

Your boiler has failed to light the gas flame and has locked itself out for safety.

High DIY-safe £100-£250

What to check first

  1. Check that your gas supply is turned on and other gas appliances are working.
  2. Press and hold the Reset button for 2 seconds then release.
  3. Wait for the boiler to attempt to restart; repeat up to three times if it fails.

Parts commonly replaced

  • Ignition Electrode
  • Gas Valve
  • Printed Circuit Board (PCB)

Related codes

Full explanation for E01
E02

Your boiler has switched itself off because it has detected that it is getting too hot, likely due to a circulation problem or a temporary blockage.

High DIY-safe £100-£250

What to check first

  1. Check that all radiator valves are fully open to allow water to flow.
  2. Ensure the system pressure is between 1.0 and 1.5 bar on the pressure gauge.
  3. Try to reset the boiler by turning the control knob to the 'R' position for a few seconds and then back to 'On'.

Parts commonly replaced

  • Safety limit thermostat
  • Pump
  • Main heat exchanger

Related codes

Full explanation for E02
E03

Your boiler has detected that a safety sensor or fuse in the exhaust system has failed or overheated, causing the unit to shut down for safety.

High Engineer only £120-£220

Parts commonly replaced

  • Flue NTC Temperature Sensor
  • Thermal Fuse
  • Wiring Harness

Related codes

Full explanation for E03
E04

Your boiler has detected that water is not circulating correctly through the system, preventing it from heating up safely.

High DIY-safe £120-220

What to check first

  1. Check that the central heating valves under the boiler are fully open
  2. Ensure your radiator valves are turned on and not stuck closed
  3. Check the boiler pressure gauge and top it up to 1.5 bar if it is too low
  4. Restart the boiler using the reset dial

Parts commonly replaced

  • Primary flow switch
  • Circulation pump
  • Flow switch diaphragm

Related codes

Full explanation for E04
E05

Your boiler has stopped working because the internal fan, which safely exhausts gases outside, is not spinning correctly.

High Engineer only £180-£350

Parts commonly replaced

  • Fan assembly
  • Air pressure switch
  • Main PCB

Related codes

Full explanation for E05
Showing 11–20 of 37
E06

Your boiler's central heating sensor has stopped working correctly, which means the system cannot monitor and control the water temperature for your radiators.

High Engineer only £90-160

Parts commonly replaced

  • Central heating NTC temperature probe
  • Wiring harness

Related codes

Full explanation for E06
E07

Your boiler has lost the ability to measure the temperature of your hot water, which usually means your taps and showers will run cold.

High Engineer only £90-160

Parts commonly replaced

  • Domestic Hot Water (DHW) NTC thermistor
  • Connecting wiring harness

Related codes

Full explanation for E07
E08

Your boiler has detected that the exhaust gases are getting too hot, causing the system to shut down for safety.

High Engineer only £120-250

Parts commonly replaced

  • Flue NTC sensor
  • Main heat exchanger
  • Burner gasket

Related codes

Full explanation for E08
E14

Your boiler has stopped working because it cannot detect water moving through the system, often caused by low pressure or trapped air.

High DIY-safe £90-220

What to check first

  1. Check the pressure gauge and top up to 1.5 bar if it is below 1.0
  2. Bleed all radiators to remove trapped air from the system
  3. Ensure all isolation valves under the boiler are fully open

Parts commonly replaced

  • Primary Flow Switch
  • Circulation Pump
  • Flow Switch Diaphragm

Related codes

Full explanation for E14
E22

Your boiler's internal computer has suffered a hardware failure and can no longer control the heating or hot water safely.

High Engineer only £250-£400

Parts commonly replaced

  • Main Printed Circuit Board (PCB)

Related codes

Full explanation for E22
E24

Your boiler is failing to light the gas flame despite several attempts, meaning it cannot provide heat or hot water.

High DIY-safe £100-£350

What to check first

  1. Check if other gas appliances in your home, like a hob, are working to confirm your gas supply is active
  2. Ensure your gas meter has credit if you use a prepay meter
  3. Press and hold the Reset button for 2-5 seconds to see if the boiler restarts

Parts commonly replaced

  • Ignition electrode
  • Flame sensing electrode
  • Gas valve
  • Printed Circuit Board (PCB)

Related codes

Full explanation for E24
E31

Your boiler is having trouble 'talking' to your thermostat or remote control panel, meaning it isn't receiving the signals to turn on or off.

High DIY-safe £60-180

What to check first

  1. Check if the batteries in your room thermostat or remote controller need replacing.
  2. Ensure the remote control unit is within range of the boiler and hasn't been moved.
  3. Check for any loose cables connecting the remote unit to the boiler wall base.
  4. Turn the boiler power off and back on at the fused spur to reset the connection.

Parts commonly replaced

  • Batteries
  • Remote control unit
  • Boiler interface PCB

Related codes

Full explanation for E31
E32

Your boiler's main internal computer brain is confused or has lost its settings, preventing the unit from working correctly.

High Engineer only £280-450

Parts commonly replaced

  • Main PCB (Printed Circuit Board)
  • PCB Connector Pins

Related codes

Full explanation for E32
ER + 14 + Reset

Your boiler has detected a failure with the internal fan or the system that clears exhaust gases, preventing the unit from lighting safely.

High Engineer only £150-£350

Parts commonly replaced

  • Fan assembly
  • Air pressure switch
  • Main PCB
Full explanation for ER + 14 + Reset
ER + 25 + Reset

Your boiler has stopped working because it has detected an overheating issue, likely due to a lack of water flow or a circulation problem.

High Engineer only £120-£350

Parts commonly replaced

  • Overheat Thermostat
  • Circulation Pump
  • NTC Temperature Sensor
Full explanation for ER + 25 + Reset
Showing 21–30 of 37
ER + 69

Your boiler has detected an error with the main control board, which is preventing it from starting up correctly.

High Engineer only £250-450

Parts commonly replaced

  • Main Printed Circuit Board (PCB)
  • Wiring Harness
Full explanation for ER + 69
ER 01 + Reset

Your boiler has failed to ignite or has lost its flame, which means it has locked itself out for safety.

High DIY-safe £120-300

What to check first

  1. Check that your gas supply is turned on and other gas appliances have fuel.
  2. Press and hold the Reset button for 2 to 3 seconds until the error clears.
  3. Ensure the condensate pipe (the plastic pipe outside) isn't frozen if it is currently winter.

Parts commonly replaced

  • Ignition electrode
  • Flame sensing probe
  • Gas valve
Full explanation for ER 01 + Reset
ER 02 + Reset

Your boiler has sensed that it is becoming too hot and has shut itself down as a safety precaution.

High DIY-safe £120-280

What to check first

  1. Wait 15 minutes for the boiler to cool down fully.
  2. Turn the selector switch to the 'Reset' position for a few seconds, then back to the heater/tap icon.
  3. Check that your radiator valves are open and that the system pressure is between 1 and 1.5 bar.

Parts commonly replaced

  • Overheat Thermostat
  • Circulation Pump
  • Main Heat Exchanger
Full explanation for ER 02 + Reset
ER 03 + Reset

Your boiler has detected a problem with how it disposes of waste gases, which has caused it to shut down for safety.

High Engineer only £100-280

Parts commonly replaced

  • Air Pressure Switch
  • Fan Assembly
  • Flue Venturi
  • PCB
Full explanation for ER 03 + Reset
ER 10 + reset

Your boiler has detected low water pressure in the system, which prevents it from firing up to provide heating or hot water.

High DIY-safe £0-160

What to check first

  1. Locate the filling loop (the flexible silver hose) underneath the boiler.
  2. Slowly open the valve or valves on the filling loop until you hear water entering the system.
  3. Monitor the pressure gauge until it reaches between 1.0 and 1.5 bar, then close the valves tightly.
  4. Press the reset button to clear the fault code.

Parts commonly replaced

  • Filling loop valve
  • Water pressure switch
  • Expansion vessel
Full explanation for ER 10 + reset
Fan rpm not exact

Your boiler is unable to start or stay on because the internal fan is not spinning at the correct speed to safely clear away exhaust fumes.

High Engineer only £180-350

Parts commonly replaced

  • Fan Assembly
  • Printed Circuit Board (PCB)
  • Venturi Tube

Related codes

Full explanation for Fan rpm not exact
Flue temperature probe lockout

Your boiler has shut down completely because it detected that the exhaust gases were becoming too hot, which is a safety protocol to protect the internal components.

High Engineer only £120-£240

Parts commonly replaced

  • Flue Temperature Probe
  • Main Heat Exchanger
  • NTC thermistor
Full explanation for Flue temperature probe lockout
Ignition failure

Your boiler is failing to light the gas to create heat, causing the system to shut down safely and display a lockout light.

High DIY-safe £100-£280

What to check first

  1. Check if other gas appliances in your home, like a hob, are working to ensure gas supply.
  2. Verify that your prepaid gas meter has credit, if applicable.
  3. Press the reset button on the boiler control panel once to attempt a restart.

Parts commonly replaced

  • Ignition Electrode
  • Gas Valve
  • Ignition PCB

Related codes

Full explanation for Ignition failure
LD1

Your boiler has lost its flame or failed to light, usually due to a lack of gas or a detection fault, meaning you have no heating or hot water.

High DIY-safe £100-280

What to check first

  1. Check if your gas prepay meter has credit available.
  2. Verify that other gas appliances, like a hob, are working correctly.
  3. Press the Reset button on the control panel to see if the boiler restarts.

Parts commonly replaced

  • Ignition Electrode
  • Gas Valve
  • Printed Circuit Board (PCB)

Related codes

Full explanation for LD1
LD2

Your boiler has detected an internal communication or wiring fault which is preventing it from firing up correctly.

High Engineer only £120-280

Parts commonly replaced

  • Main PCB
  • Wiring Loom

Related codes

Full explanation for LD2
Showing 31–37 of 37
LD3

Your boiler has detected an internal electrical communication error or a fault with the main circuit board.

High Engineer only £200-£350

Parts commonly replaced

  • Main PCB (Printed Circuit Board)
  • Wiring harness

Related codes

Full explanation for LD3
LD4

Your boiler's internal computer brain is reporting a critical communication or hardware failure, meaning the system cannot safely operate.

High Engineer only £280-£450

Parts commonly replaced

  • Main Printed Circuit Board (PCB)
  • Wiring harness

Related codes

Full explanation for LD4
Li

Your boiler has detected that the water inside has become far too hot, causing it to shut down for safety purposes.

High Engineer only £90-250

Parts commonly replaced

  • Overheat Thermostat
  • Circulation Pump
  • NTC Temperature Sensor
Full explanation for Li
Lock-out

Your boiler has switched itself off because it has detected that the water inside has become dangerously hot.

High DIY-safe £100-280

What to check first

  1. Check that all radiator valves are fully open to allow water to flow.
  2. Ensure there is enough water pressure in the system by checking the pressure gauge.
  3. Wait for the boiler to cool down and press the reset button on the control panel.

Parts commonly replaced

  • Circulation Pump
  • Overheat Thermostat
  • Primary Heat Exchanger
Full explanation for Lock-out
Lock-out state

Your boiler has attempted to light itself four times without success and has turned itself off for safety.

High DIY-safe £100-350

What to check first

  1. Check if other gas appliances in your home, like a cooker, are working to confirm gas supply.
  2. Ensure your gas meter has credit and the emergency control valve is open.
  3. Press the reset button on the front control panel once to attempt a restart.

Parts commonly replaced

  • Ignition Electrode
  • Gas Valve
  • Ignition PCB

Related codes

Full explanation for Lock-out state
LP

Your boiler has detected that the water pressure is too low to operate safely.

High DIY-safe £0-120

What to check first

  1. Locate the filling loop valves underneath the boiler.
  2. Slowly open both valves to allow water into the system.
  3. Watch the pressure gauge and close the valves once it reaches between 1 and 1.5 bar.
  4. Ensure both valves are fully closed and reset the boiler if necessary.

Parts commonly replaced

  • Filling loop
  • Expansion vessel
  • Pressure sensor
Full explanation for LP
Safety thermostat lockout

Your boiler has switched itself off to prevent overheating, likely due to a circulation issue or a component getting too hot.

High DIY-safe £120-250

What to check first

  1. Check that all radiator valves are open and not turned off.
  2. Ensure there is enough water pressure in the system (check the gauge is between 1 and 1.5 bar).
  3. Turn the control knob to the 'Reset' position, wait for a few seconds, then turn it back to the desired setting.

Parts commonly replaced

  • Overheat Thermostat
  • Circulation Pump
  • Thermistor (NTC Sensor)
Full explanation for Safety thermostat lockout