Biasi Riva Compact HE M96a Fault codes & diagnostics

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

Combi Natural GasLPG 24-28 kW 2008-2012 Discontinued

Replaced by: Advance Plus

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.
16 High 1 Medium 3 Low
Just want the most common Biasi Riva Compact HE M96a faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 20 documented codes

Tap any card for details

LED / flash-pattern codes
Lock-out signal lamp E blinks

Your boiler has entered a configuration mode and needs its settings saved before it can function normally again.

Medium Engineer only £80-140

Parts commonly replaced

  • Gas Valve
  • PCB (Printed Circuit Board)
Full explanation for Lock-out signal lamp E blinks
Operation lights flashing

Your boiler is starting up briefly but then switching itself off because it is struggling to safely expel waste gases or drain excess condensation.

High DIY-safe £100-280

What to check first

  1. Check the white plastic condensate pipe outside for signs of freezing or blockages
  2. Thaw a frozen external pipe using warm (not boiling) water or a heat pack
  3. Ensure the external flue terminal is not obstructed by debris, snow, or vegetation

Parts commonly replaced

  • Air Pressure Switch
  • Condensate Trap
  • Fan Assembly
  • Venturi Tube
Full explanation for Operation lights flashing
Red Led Flashing

Your boiler is failing to light the gas flame despite several attempts, causing it to shut down for safety.

High DIY-safe £100-280

What to check first

  1. Check if other gas appliances, like a cooker hob, are working to ensure gas supply is active.
  2. Verify that your gas meter has credit if you use a pre-payment meter.
  3. Press the reset button on the front panel once to see if the boiler restarts.

Parts commonly replaced

  • Ignition Electrode
  • Gas Valve
  • Printed Circuit Board (PCB)
Full explanation for Red Led Flashing
Digital codes
1 second ON 1 second OFF

Your boiler is currently operating normally and is simply indicating that it is actively heating your radiators or hot water.

Low DIY-safe £0

What to check first

  1. Check your thermostat to see if it is calling for heat
  2. Turn on a hot tap to confirm the boiler responds
  3. No action is required as this is a status indicator, not a fault
Full explanation for 1 second ON 1 second OFF
A fault on gas supply

Your boiler has stopped working because it cannot detect a steady supply of gas or a flame.

High DIY-safe £100-350

What to check first

  1. Check if other gas appliances, like a cooker, are working to confirm gas supply to the house.
  2. Verify that your gas meter has credit if it is a pre-payment type.
  3. Locate the reset knob on the front panel and turn it to the 'R' position for a few seconds.

Parts commonly replaced

  • Gas Valve
  • Ignition Electrode
  • Flame Sensing Electrode
  • Printed Circuit Board (PCB)
Full explanation for A fault on gas supply
A short pulse every 4 seconds

Your boiler is currently switched off but is working correctly to protect itself from freezing during cold weather.

Low DIY-safe £0

What to check first

  1. Turn the main selector switch to the 'ON', 'Summer', or 'Winter' position to begin normal operation.
  2. Ensure your external room thermostat is turned up if you require heating.
  3. No action is required if you intended for the boiler to stay off, as the light simply confirms frost protection is active.
Full explanation for A short pulse every 4 seconds
All operation lights OFF

Your boiler appears to have no power and is completely unresponsive when you try to use your heating or hot water.

High DIY-safe £100-350

What to check first

  1. Check if the boiler's fused spur switch is turned on
  2. Check your home's main consumer unit (fuse box) for a tripped circuit breaker
  3. Replace the 3-amp fuse in the boiler's external electrical spur

Parts commonly replaced

  • External 3A Fuse
  • Printed Circuit Board (PCB)
  • Internal Glass Fuse
Full explanation for All operation lights OFF
Faulty air pressure sensor

Your boiler has detected an issue with the system that moves air and exhaust fumes, causing it to stop running for your safety.

High Engineer only £120-220

Parts commonly replaced

  • Air Pressure Switch
  • Venturi Tube
  • Fan Assembly
Full explanation for Faulty air pressure sensor
Faulty flame detection

Your boiler is struggling to confirm that the burner has lit correctly, so it has shut down as a safety precaution.

High Engineer only £120-220

Parts commonly replaced

  • Flame detection electrode
  • Ignition lead
  • Printed Circuit Board (PCB)
Full explanation for Faulty flame detection
Faulty ignition

Your boiler is struggling to light the gas, which means you won't have any heating or hot water until the ignition system is fixed.

High Engineer only £120-240

Parts commonly replaced

  • Ignition electrodes
  • Ignition lead
  • Printed Circuit Board (PCB)
Full explanation for Faulty ignition
Showing 11–20 of 20
Faulty modulation gas valve

Your boiler is unable to control the flow of gas correctly, which means it cannot fire up to provide heating or hot water.

High Engineer only £180-320

Parts commonly replaced

  • Gas Valve
  • Printed Circuit Board (PCB)
  • Wiring Harness
Full explanation for Faulty modulation gas valve
Flame detection error

Your boiler is failing to recognize that a flame has been lit, causing it to shut down for safety purposes.

High Engineer only £120-350

Parts commonly replaced

  • Flame sensing electrode
  • Ignition lead
  • Gas valve
  • Printed Circuit Board (PCB)
Full explanation for Flame detection error
Gas injectors blocked

Your boiler has stopped working because the gas burners are clogged and cannot ignite the fuel properly.

High Engineer only £90-180

Parts commonly replaced

  • Gas Injectors
  • Burner Assembly
  • Gas Valve
Full explanation for Gas injectors blocked
Lack of burner ignition

Your boiler is trying to start up but cannot create or detect a flame, leaving you without heating and hot water.

High DIY-safe £120-350

What to check first

  1. Check that your gas emergency control valve is open and you have credit on your meter.
  2. Check if other gas appliances in your home, like a hob, are working correctly.
  3. Press the reset button on the front control panel to see if the boiler restarts.

Parts commonly replaced

  • Ignition Electrode
  • Gas Valve
  • Printed Circuit Board (PCB)
  • Flame Sensing Electrode
Full explanation for Lack of burner ignition
lock-out signal lamp

Your boiler has stopped working for safety reasons and needs to be manually restarted to attempt to fire up again.

High DIY-safe £100-350

What to check first

  1. Locate the reset button (often marked with an 'R' or a flame symbol) on the boiler control panel.
  2. Press and hold the reset button for 2 to 5 seconds.
  3. Wait for the boiler to attempt the ignition sequence; if it fails to start after three attempts, call a Gas Safe engineer.

Parts commonly replaced

  • Ignition Electrode
  • Printed Circuit Board (PCB)
  • Gas Valve
Full explanation for lock-out signal lamp
Lock-out signal lamp red (ON)

Your boiler is failing to detect the flame after lighting, causing it to shut down for safety even though the burner briefly ignites.

High Engineer only £120-250

Parts commonly replaced

  • Flame sensing electrode
  • Ignition lead
  • PCB
Full explanation for Lock-out signal lamp red (ON)
Lock-out state

Your boiler has failed to light the flame after several attempts and has shut itself down for safety.

High DIY-safe £100-350

What to check first

  1. Check if other gas appliances (like a cooker) are working to ensure gas is reaching the property
  2. Check that your gas meter has credit if you use a prepaid meter
  3. Press the Reset button on the front control panel
  4. Ensure the condensate pipe (outside white plastic pipe) isn't frozen if it is winter

Parts commonly replaced

  • Ignition Electrode
  • Gas Valve
  • Printed Circuit Board (PCB)
Full explanation for Lock-out state
ON

Your boiler is operating normally and is currently responding to a request for heating or hot water.

Low DIY-safe £0

What to check first

  1. Check your thermostat or programmer to see if they are calling for heat
  2. Run a hot tap to see if the boiler responds normally
  3. No action is required as this is a status indicator, not a fault code
Full explanation for ON
Other faults

Your boiler's internal computer brain has detected a specific internal electrical fault that it cannot categorise under standard error lights.

High Engineer only £180-350

Parts commonly replaced

  • Main Electronic Control P.C.B.
  • Wiring Harness
  • Ignition Electrode
Full explanation for Other faults
Safety thermostat lockout

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. Wait at least 20 minutes for the boiler to cool down completely.
  2. Check that your radiator valves are open and not turned to '0'.
  3. Press the reset button on the front control panel.
  4. Ensure your boiler system pressure is between 1.0 and 1.5 bar on the pressure gauge.

Parts commonly replaced

  • Overheat Thermostat
  • Circulation Pump
  • Primary Heat Exchanger
Full explanation for Safety thermostat lockout