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

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

Combi Natural Gas 24 kW 2002 onwards Discontinued

Replaced by: Biasi Riva Plus

The Riva Compact 24S (M90E.24S) range comes in 3 types

Pick the one you have. The fault codes, GC numbers and manual differ by type.

Each model has its own manual A family spans several manuals, one per model or generation. Pick your model above and its page has the manual its fault codes were read from.

The fault code is already on your display

Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →

Severity at a glance

Each cell = one fault code. Hover to identify.
7 Emergency 12 High 4 Medium

All 23 documented codes

Tap any card for details

164-026

Your boiler has detected an issue with a temperature sensor, which stops it from properly monitoring how hot the water is getting.

Medium Engineer only £90-180 Shared across the Riva range

Parts commonly replaced

  • NTC Temperature Sensor
  • Wiring harness

Related codes

169-083

Your boiler has suffered an electrical safety fuse failure, which completely cuts power to the internal controls to prevent further damage.

High Engineer only £90-180 Shared across the Riva range

Parts commonly replaced

  • Internal 1.6A T Fuse
  • Printed Circuit Board (PCB)

Related codes

E00-684

Your boiler has stopped working because it cannot detect water flowing properly through the internal heating system.

High Engineer only £120-250 Shared across the Riva range

Parts commonly replaced

  • Flow switch
  • Flow switch microswitch
  • Wiring harness

Related codes

E00-688

Your boiler is not detecting the flow of water needed to provide hot water safely.

High Engineer only £120-250 Shared across the Riva range

Parts commonly replaced

  • Flow switch
  • Flow switch membrane

Related codes

E01-204

Your boiler has detected an issue related to the domestic hot water heat exchanger, which may cause your hot water to stop working properly.

High Engineer only £150-350 Shared across the Riva range

Parts commonly replaced

  • Plate heat exchanger
  • Flow sensor
  • Diverter valve

Related codes

E01-205

Your boiler has detected an issue related to the hot water heat exchanger, which may prevent your hot water from working properly.

High Engineer only £150-300 Shared across the Riva range

Parts commonly replaced

  • DHW Heat Exchanger
  • NTC Sensor
  • Flow Switch

Related codes

E83-013

Your boiler's safety pressure valve has opened or registered a fault because the internal water pressure has become too high.

Emergency Engineer only £120-250 Shared across the Riva range

Parts commonly replaced

  • Pressure Relief Valve
  • Filling Loop
  • Expansion Vessel

Related codes

E83-082

Your boiler is not properly detecting when you turn on the hot tap, so it fails to fire up and provide hot water.

Medium Engineer only £100-200 Shared across the Riva range

Parts commonly replaced

  • DHW flow switch
  • Flow switch microswitch

Related codes

E83-086

Your boiler is having trouble directing heat properly between your radiators and your taps, which usually means it is stuck providing only hot water or only heating.

High Engineer only £180-300 Shared across the Riva range

Parts commonly replaced

  • Diverter valve actuator
  • Complete diverter valve

Related codes

E83-101

Your boiler has automatically shut down because the internal safety thermostat detected that the water temperature has risen dangerously high.

Emergency Engineer only £150-300 Shared across the Riva range

Parts commonly replaced

  • Overheat thermostat
  • PCB
  • Pump

Related codes

Showing 11–20 of 23
E83-121

Your boiler is detecting an issue with the internal expansion vessel, which regulates system pressure and protects your heating pipes from bursting.

Medium Engineer only £120-250 Shared across the Riva range

Parts commonly replaced

  • Expansion Vessel
  • Pressure Relief Valve
  • Flexible Hose

Related codes

E83-122

Your boiler is struggling to reliably detect the burner flame, which usually results in the system locking out for safety.

High Engineer only £90-180 Shared across the Riva range

Parts commonly replaced

  • Ignition / Detection Electrode
  • Lead Assembly
  • PCB

Related codes

E83-126

Your boiler is failing to detect a proper flame when trying to light, causing it to lock out and stop providing heating and hot water.

High Engineer only £120-250 Shared across the Riva range

Parts commonly replaced

  • Ignition Electrode
  • Ignition Lead
  • PCB

Related codes

E83-127

Your boiler is failing to light the burner because of a fault with the ignition components, meaning you currently have no heating or hot water.

High Engineer only £120-250 Shared across the Riva range

Parts commonly replaced

  • Ignition Electrode
  • Ignition Lead
  • PCB

Related codes

E83-129

Your boiler has detected an issue with the internal gas valve, which controls the fuel supply required for heating and hot water.

Emergency Engineer only £180-350 Shared across the Riva range

Parts commonly replaced

  • Gas valve
  • PCB

Related codes

E83-142

Your boiler has failed to ignite properly and has locked out for safety reasons.

High Engineer only £150-350 Shared across the Riva range

Parts commonly replaced

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

Related codes

E83-145

Your boiler is detecting an issue with the combined temperature and pressure gauge or its wiring, meaning it cannot accurately read the system status.

Medium Engineer only £90-180 Shared across the Riva range

Parts commonly replaced

  • Pressure/temperature gauge
  • Wiring harness
  • Main PCB

Related codes

E83-178

Your boiler has detected an internal fault related to the insulation panels inside the combustion chamber, which requires a Gas Safe registered engineer to inspect and ensure safe operation.

Emergency Engineer only £150-300 Shared across the Riva range

Parts commonly replaced

  • Combustion chamber side panels
  • Insulation kit

Related codes

E83-180

Your boiler has detected an issue involving the internal combustion chamber insulation or rear panel, which is critical for safe and efficient fuel burning.

Emergency Engineer only £150-300 Shared across the Riva range

Parts commonly replaced

  • Combustion chamber rear panel
  • Insulation panel

Related codes

E83-181

Your boiler has registered an internal configuration or sensor error related to the combustion chamber components, which requires professional inspection.

High Engineer only £150-300 Shared across the Riva range

Parts commonly replaced

  • PCB
  • Combustion Chamber Insulation Panel
  • Wiring Harness

Related codes

Showing 21–23 of 23
E83-196

Your boiler has detected an issue with the seal or placement of the combustion chamber front panel, which is a critical safety component that keeps the burner gases contained.

Emergency Engineer only £90-180 Shared across the Riva range

Parts commonly replaced

  • Combustion chamber front panel seal
  • Securing clips
  • Insulation panel

Related codes

E83-197

Your boiler has detected an internal configuration mismatch or safety seal issue involving the main casing panel, which requires professional inspection to ensure it is burning safely.

Emergency Engineer only £90-180 Shared across the Riva range

Parts commonly replaced

  • Combustion chamber seal
  • Front panel assembly

Related codes

N/A

Your boiler has temporarily shut down because the water inside it has become dangerously hot, which usually points to a blockage in the flow.

High Engineer only £150-350 Shared across the Riva range

Parts commonly replaced

  • Circulating Pump
  • Automatic Bypass Valve
  • Primary Heat Exchanger

Related codes

1 operating states & engineer diagnostics

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