Biasi Riva Compact 24S (M90E.24S) Fault codes & diagnostics

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

Combi Natural Gas 24 kW 2002 onwards Discontinued
GC Number 47-970-17

Replaced by: Biasi Riva Plus

Download the Biasi Riva Compact 24S (M90E.24S) manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. PDF

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.
1 Emergency 26 High 1 Medium
Versions & GC numbers

Which version do you have?

The GC number on your boiler's data badge identifies the exact appliance and production years, as recorded in the UK Product Characteristics Database.

GC number Appliance (register name) Produced
47-970-17 Riva Compact M90E.24S 2002–present
Just want the most common Biasi Riva Compact 24S (M90E.24S) faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 28 documented codes

Tap any card for details

LED / flash-pattern codes
Flashing LD2

Your boiler has detected low water pressure or a circulation issue, preventing it from heating up to protect the system.

High DIY-safe £90-180

What to check first

  1. Check the pressure gauge on the front of the boiler; it should be between 1 and 1.5 bar.
  2. If pressure is low, use the filling loop underneath the boiler to top it up until the needle reaches 1.2 bar.
  3. Ensure all radiator valves are open and bleed any air from the radiators using a radiator key.

Parts commonly replaced

  • CH Temperature Sensor (NTC)
  • Primary Flow Switch
  • Circulation Pump

Related codes

Full explanation for Flashing LD2
LD1, LD2 Flashing

Your boiler has detected a problem with the sensor that monitors hot water temperature, which means your taps may not get warm.

Medium Engineer only £90-160

Parts commonly replaced

  • DHW Temperature Probe (NTC)
  • Connecting wiring harness
Full explanation for LD1, LD2 Flashing
LD1, LD2, LD3 Flashing

Your boiler has detected a problem with the internal temperature sensor that monitors the heating water, preventing the unit from operating correctly.

High Engineer only £90-160

Parts commonly replaced

  • C.H. Temperature Probe (NTC Sensor)
  • Wiring harness connectors

Related codes

Full explanation for LD1, LD2, LD3 Flashing
LD2, LD3 Flashing

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

High Engineer only £100-£190

Parts commonly replaced

  • Flue Gas NTC Sensor
  • Main Heat Exchanger (if scaled)

Related codes

Full explanation for LD2, LD3 Flashing
Digital codes
All operation lights OFF

Your boiler has no power and is completely unresponsive, meaning it cannot provide any heating or hot water.

High DIY-safe £90-280

What to check first

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

Parts commonly replaced

  • Printed Circuit Board (PCB)
  • Internal Fuses
  • External Spurred Socket Fuse
Full explanation for All operation lights OFF
E00---684

Your boiler has detected that water isn't moving through the system properly, which has caused it to shut down to prevent overheating.

High Engineer only £120-£280

Parts commonly replaced

  • Primary Flow Switch
  • Circulation Pump
  • Diverter Valve Membrane
Full explanation for E00---684
E00---688

Your boiler has detected that water isn't moving through the system properly, meaning it won't fire up to provide heating or hot water until the internal pressure sensor is triggered.

High Engineer only £90-160

Parts commonly replaced

  • Main flow switch membrane
  • Diverter valve diaphragm
  • Flow switch microswitch
Full explanation for E00---688
E01---204

Your boiler has detected a problem with the internal part that heats your water, often caused by a blockage or a faulty sensor, meaning you will likely have no hot water.

High Engineer only £180-£350

Parts commonly replaced

  • Domestic Hot Water Plate Heat Exchanger
  • DHW Temperature Sensor (NTC)
  • Diverter Valve Valve Actuator
Full explanation for E01---204
E01---205

Your boiler is failing to heat your tap water correctly because the internal heat exchanger is likely blocked or faulty.

High Engineer only £180-350

Parts commonly replaced

  • Domestic Hot Water Heat Exchanger
  • DHW Temperature Sensor
  • Diverter Valve Assembly
Full explanation for E01---205
E83---013

Your boiler has shut down because a safety component has detected an internal pressure issue, likely caused by a communication error or a faulty sensor.

High Engineer only £120-250

Parts commonly replaced

  • Safety pressure switch
  • Main PCB
  • Pressure sensor
Full explanation for E83---013
Showing 11–20 of 28
E83---082

Your boiler is not detecting when you turn on a hot tap, so it isn't starting up to provide hot water.

High Engineer only £90-160

Parts commonly replaced

  • DHW Flow Switch
  • Switch Membrane
  • Flow Sensor Cable
Full explanation for E83---082
E83---086

Your boiler is having trouble switching between heating your radiators and providing hot water because of an electrical fault with an internal valve.

High Engineer only £140-£260

Parts commonly replaced

  • 3-way diverter valve actuator
  • Diverter valve motor
Full explanation for E83---086
E83---101

Your boiler has become too hot and has shut itself down as a safety precaution to prevent damage.

High DIY-safe £120-280

What to check first

  1. Check that all radiator valves are fully open
  2. Ensure the system water pressure is between 1 and 1.5 bar
  3. Wait for the boiler to cool down and press the 'Reset' button

Parts commonly replaced

  • Overheat Thermostat
  • Circulation Pump
  • Main Heat Exchanger (Cleaning or Replacement)
Full explanation for E83---101
E83---121

Your boiler is struggling to manage the internal pressure changes as the water heats up, which is causing the system to shut down.

High Engineer only £120-250

Parts commonly replaced

  • Expansion Vessel
  • Schrader Valve
  • Flexible Hose
Full explanation for E83---121
E83---122

Your boiler is failing to detect the flame needed to heat your water and radiators, causing the system to shut down for safety.

High Engineer only £120-£220

Parts commonly replaced

  • Detection electrode
  • Ignition lead
  • Gas valve

Related codes

Full explanation for E83---122
E83---126

Your boiler is failing to light the gas properly because the component responsible for creating the starting spark is faulty or worn out.

High Engineer only £120-£210

Parts commonly replaced

  • Ignition Electrode
  • Ignition Lead
  • Printed Circuit Board (PCB)

Related codes

Full explanation for E83---126
E83---127

Your boiler is struggling to light the burner because the part responsible for creating the internal spark is failing or dirty.

High Engineer only £120-210

Parts commonly replaced

  • Ignition Electrode
  • Ignition Lead
  • Spark Generator

Related codes

Full explanation for E83---127
E83---129

Your boiler is unable to safely control the flow of gas required to light the burner, meaning your heating and hot water will not work.

High Engineer only £180-£320

Parts commonly replaced

  • Gas valve
  • Printed Circuit Board (PCB)
  • Wiring harness
Full explanation for E83---129
E83---142

Your boiler is failing to light the gas burner correctly to provide heating and hot water.

High Engineer only £150-£350

Parts commonly replaced

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

Related codes

Full explanation for E83---142
E83---178

Your boiler has detected an internal insulation issue or a heat-related fault that requires a professional safety inspection of the main central heating components.

High Engineer only £120-280

Parts commonly replaced

  • Combustion Chamber Insulation Panels
  • Heat Exchanger Seals
  • Overheat Thermostat
Full explanation for E83---178
Showing 21–28 of 28
E83---180

Your boiler has detected a potential structural issue or heat damage within the internal combustion chamber, causing it to shut down for safety.

High Engineer only £150-350

Parts commonly replaced

  • Combustion chamber rear insulation panel
  • Burner gasket
  • Heat exchanger
Full explanation for E83---180
E83---181

Your boiler has detected a physical issue or insulation failure within the main combustion chamber, which is preventing it from heating safely.

High Engineer only £180-350

Parts commonly replaced

  • Combustion chamber rear panel insulation
  • Burner gasket
  • Heat exchanger seals

Related codes

Full explanation for E83---181
E83---196

Your boiler has detected a potential safety issue or an internal communication error involving the front panel of the combustion area.

High Engineer only £120-250

Parts commonly replaced

  • Main PCB
  • Combustion Chamber Insulation
  • Wiring Harness

Related codes

Full explanation for E83---196
E83---197

Your boiler has detected a potential safety issue with the seal or position of the main burner cover, which is preventing it from firing safely.

Emergency Engineer only £120-280

Parts commonly replaced

  • Combustion chamber seal
  • Front panel insulation gasket
  • Burner assembly fasteners
Full explanation for E83---197
Faulty primary circuit

Your boiler has lost water pressure or the water isn't moving through the system properly, which has triggered a safety shutdown to prevent overheating.

High DIY-safe £100-£250

What to check first

  1. Check the pressure gauge on the front of the boiler; it should be between 1 and 1.5 bar.
  2. If the pressure is low, use the filling loop valves underneath the boiler to top it up.
  3. Ensure all radiator valves and lockdowns are open to allow water to flow.
  4. Restart the boiler once the correct pressure is reached.

Parts commonly replaced

  • Circulating Pump
  • Primary Pressure Switch
  • Flow Temperature Sensor
Full explanation for Faulty primary circuit
Lack of burner ignition

Your boiler is failing to light the gas flame required to heat your water and radiators.

High DIY-safe £120-£350

What to check first

  1. Check that your gas emergency control valve is in the 'on' position
  2. If you have a prepayment meter, check that you have sufficient credit
  3. Press and hold the reset button for at least two seconds

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Printed Circuit Board (PCB)
Full explanation for Lack of burner ignition
Lock-out signal lamp red

Your boiler has failed to light the burner after several attempts and has shut down as a safety precaution.

High DIY-safe £100-280

What to check first

  1. Check that your gas supply is turned on at the meter
  2. Ensure any other gas appliances in the home are working correctly
  3. Press and hold the reset button for at least two seconds
  4. Check if the system pressure gauge is between 1 and 1.5 bar

Parts commonly replaced

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

Related codes

Full explanation for Lock-out signal lamp red
Status & diagnostic codes

8 operating states & engineer diagnostics

Not faults — these are normal operating states. Tap to expand.

Flashing LD1 Status Your boiler is operating normally and performing a routine check to ensure everything is working correctly. 1 second ON / 1 second OFF Status Your boiler is operating normally and is currently responding to a demand for heating or hot water. A short pulse every 4 seconds Status Your boiler is currently on standby and is performing its normal automatic safety check to prevent the internal pipes from freezing. C.h. operation Status Your boiler is currently running in central heating mode and this light is a normal status indicator rather than a fault. D.h.w. operation Status Your boiler is currently providing hot water but ignoring heating demands, or it may have a sensor glitch causing it to stay in hot water mode. E01 Diagnostic Your boiler has failed to ignite, which means it cannot provide heat or hot water and requires a safety reset. Frost protect operation Status Your boiler has sensed very cold temperatures and is running its internal pump or burner to prevent its pipes from freezing. Normally operating boiler Status Your boiler is currently working as it should and is simply communicating that it is in normal operating mode for the season you have selected.