Biasi Rinnova Adaptive 25C M300V.2025 SM Fault codes & diagnostics

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

Natural Gas
GC Number 47-583-46
Download the Biasi Rinnova Adaptive 25C M300V.2025 SM manualThe official installation and service manual (PDF), the document these fault codes were read from. PDF

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Severity at a glance

Each cell = one fault code. Hover to identify.
1 Emergency 37 High
Fault codes

All 38 documented codes

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E01

Your boiler has temporarily stopped working because it failed to ignite safely.

High DIY-safe £90-250

What to check first

  1. Check if your gas supply is working by testing another gas appliance like a hob.
  2. Check your gas prepayment meter to ensure you have credit.
  3. Locate the reset button on your boiler, press and hold it for 5 seconds, and release to see if it restarts.

Parts commonly replaced

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

Related codes

Full explanation for E01
E02

Your boiler has temporarily stopped working as a safety precaution due to an internal lock-out, meaning you currently have no heating or hot water.

High DIY-safe £90-250

What to check first

  1. Locate the reset button or turn the mode selector to the reset position on your Biasi boiler.
  2. Hold or turn the reset control for 2 to 5 seconds to clear the lock-out.
  3. Wait to see if the boiler fires up normally; if the code returns immediately, do not keep resetting it.

Parts commonly replaced

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

Related codes

Full explanation for E02
E03

Your boiler has safely shut itself down because it cannot detect a proper flame or exhaust the waste gases correctly.

High Engineer only £100-£250

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Printed circuit board (PCB)

Related codes

Full explanation for E03
E04

Your boiler has temporarily stopped working for safety reasons, usually because it cannot detect a flame or has lost water pressure.

High Engineer only £100-£250

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • PCB

Related codes

Full explanation for E04
E05

Your boiler has safety-locked itself because it is having trouble detecting or maintaining a flame.

High DIY-safe £100-£250

What to check first

  1. Check that your gas pre-payment meter has credit (if applicable)
  2. Check that other gas appliances in your home, like a hob, are working correctly
  3. Press and hold the 'Reset' button for five seconds to attempt to restart the boiler

Parts commonly replaced

  • Ignition electrode
  • Flame sensing electrode
  • Gas valve

Related codes

Full explanation for E05
E06

Your boiler has safely shut itself down due to a general internal error and requires a manual reset or professional attention to get running again.

High DIY-safe £90-200

What to check first

  1. Check the system pressure gauge is between 1 and 1.5 bar.
  2. Locate the reset button or turn the mode selector to the reset position.
  3. Hold the reset button for 2-5 seconds to clear the lockout.

Parts commonly replaced

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

Related codes

Full explanation for E06
E07

Your boiler has safely locked itself out and stopped working because it has detected a safety or operational fault that needs attention.

High Engineer only £150-350

Parts commonly replaced

  • Printed Circuit Board (PCB)
  • Flame sensor electrode
  • Gas valve

Related codes

Full explanation for E07
E08

Your boiler has temporarily shut itself down for safety because it has detected a recurring operational issue.

High Engineer only £100-250

Parts commonly replaced

  • Gas valve
  • Main printed circuit board
  • Ignition electrode

Related codes

Full explanation for E08
E10

Your boiler has safely shut itself down because it has detected a safety lockout, meaning it will not produce heat or hot water until the issue is cleared.

High DIY-safe £90-250

What to check first

  1. Check your gas supply by testing another gas appliance like a cooker.
  2. Inspect the condensate pipe outside to ensure it is not frozen or blocked.
  3. Locate the reset button or turn the mode dial to reset, and hold it for a few seconds to see if the boiler restarts.

Parts commonly replaced

  • Gas Valve
  • Ignition Electrode
  • Printed Circuit Board

Related codes

Full explanation for E10
E11

Your boiler is detecting a flame inside when it shouldn't be burning, so it has safely locked out to prevent any issues.

Emergency Engineer only £150-300

Parts commonly replaced

  • Gas valve
  • Printed circuit board (PCB)
  • Electrodes

Related codes

Full explanation for E11
Showing 11–20 of 38
E12

Your boiler has safely shut itself down due to a general safety lock-out, meaning it has stopped working until the underlying issue is cleared.

High Engineer only £100-250

Parts commonly replaced

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

Related codes

Full explanation for E12
E13

Your boiler has completely stopped working and locked itself out for safety reasons due to an internal fault.

High Engineer only £150-300

Parts commonly replaced

  • PCB
  • Gas Valve
  • Ignition Lead

Related codes

Full explanation for E13
E14

Your boiler has temporarily stopped working and locked itself out as a safety precaution due to an internal fault.

High Engineer only £150-300

Parts commonly replaced

  • Main PCB
  • NTC Sensor
  • Ignition Electrode

Related codes

Full explanation for E14
E18

Your boiler has completely stopped working and locked itself for safety due to a persistent internal fault.

High Engineer only £150-300

Parts commonly replaced

  • Printed Circuit Board
  • Ignition Electrode
  • Gas Valve

Related codes

Full explanation for E18
E19

Your boiler has completely stopped working and locked itself for safety due to a recurring operational fault that it cannot clear on its own.

High Engineer only £150-350

Parts commonly replaced

  • Gas valve
  • Printed Circuit Board (PCB)
  • Electrode assembly

Related codes

Full explanation for E19
E20

Your boiler has safely locked itself out to prevent damage because it cannot ignite properly.

High Engineer only £150-300

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • PCB

Related codes

Full explanation for E20
E21

Your boiler has temporarily shut down and locked itself for safety due to a failure to ignite or a detected system error.

High Engineer only £100-250

Parts commonly replaced

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

Related codes

Full explanation for E21
E22

Your boiler has safely shut itself down due to a safety lock-out, meaning it has stopped working until the underlying issue is resolved.

High Engineer only £100-£250

Parts commonly replaced

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

Related codes

Full explanation for E22
E23

Your boiler has safely shut down and locked itself to prevent operation due to a safety fault.

High Engineer only £150-300

Parts commonly replaced

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

Related codes

Full explanation for E23
E24

Your boiler has safely shut itself down due to a safety lock-out, meaning it needs to be manually reset or checked by a professional.

High Engineer only £100-250

Parts commonly replaced

  • PCB
  • Ignition Electrode
  • Gas Valve

Related codes

Full explanation for E24
Showing 21–30 of 38
E25

Your boiler has temporarily stopped working for safety reasons and needs to be reset.

High DIY-safe £90-200

What to check first

  1. Locate the reset button or turn the mode selector to the reset position on your boiler's control panel.
  2. Hold the reset button for 2 to 5 seconds and release it.
  3. Wait a moment to see if the boiler fires up and resumes normal operation.

Parts commonly replaced

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

Related codes

Full explanation for E25
E26

Your boiler has temporarily stopped working and locked itself out for safety, meaning you currently have no heating or hot water.

High Engineer only £100-250

Parts commonly replaced

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

Related codes

Full explanation for E26
E40

Your boiler has completely stopped working and locked itself out as a safety precaution due to a persistent internal fault.

High Engineer only £150-350

Parts commonly replaced

  • Main PCB
  • Electrode assembly
  • Gas valve

Related codes

Full explanation for E40
E42

Your boiler has completely stopped working and locked itself out for safety because it has detected an internal fault that it cannot resolve on its own.

High Engineer only £150-350

Parts commonly replaced

  • PCB
  • Gas valve
  • Electrode assembly

Related codes

Full explanation for E42
E44

Your boiler has completely stopped working and locked itself out for safety, meaning you currently have no heating or hot water.

High Engineer only £150-350

Parts commonly replaced

  • PCB
  • Ignition electrode
  • Gas valve

Related codes

Full explanation for E44
E50

Your boiler has temporarily stopped working and locked itself for safety due to a general fault it has detected.

High Engineer only £100-250

Parts commonly replaced

  • Main control board
  • Ignition electrode
  • Gas valve

Related codes

Full explanation for E50
E62

Your boiler has completely stopped working and locked itself out for safety because it has detected an internal fault that it cannot clear on its own.

High Engineer only £150-350

Parts commonly replaced

  • Printed Circuit Board (PCB)
  • Flame sensor
  • Gas valve

Related codes

Full explanation for E62
E65

Your boiler has completely stopped working and locked itself down for safety reasons.

High Engineer only £150-300

Parts commonly replaced

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

Related codes

Full explanation for E65
E68

Your boiler has safely shut itself down due to a safety lock-out, meaning it has stopped working until the underlying issue is resolved.

High Engineer only £150-300

Parts commonly replaced

  • PCB
  • Gas valve
  • Electrode assembly

Related codes

Full explanation for E68
E77

Your boiler has completely stopped working and locked itself out for safety reasons due to a serious internal fault.

High Engineer only £150-350

Parts commonly replaced

  • Main PCB
  • Gas valve
  • Electrode assembly

Related codes

Full explanation for E77
Showing 31–38 of 38
E78

Your boiler has completely stopped working and locked itself out for safety, meaning you currently have no heating or hot water.

High Engineer only £150-300

Parts commonly replaced

  • Main Control Board
  • Gas Valve
  • Electrode Assembly

Related codes

Full explanation for E78
E79

Your boiler has safely shut itself down due to a safety lock-out, meaning it needs to be manually reset or inspected by a professional before it can run again.

High Engineer only £90-250

Parts commonly replaced

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

Related codes

Full explanation for E79
E89

Your boiler has completely stopped working and locked itself down for safety because it has detected a serious internal fault.

High Engineer only £150-350

Parts commonly replaced

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

Related codes

Full explanation for E89
E91

Your Biasi boiler has completely stopped working and locked itself out for safety reasons.

High Engineer only £100-£250

Parts commonly replaced

  • Main PCB
  • Internal fuse
  • Ignition electrode

Related codes

Full explanation for E91
E96

Your boiler has detected an issue with the electrical power supply frequency, which prevents it from operating safely.

High Engineer only £100-£350

Parts commonly replaced

  • Main Printed Circuit Board (PCB)
  • External voltage regulator

Related codes

Full explanation for E96
E97

Your boiler has suffered a safety lock-out and stopped working to protect itself and your home.

High Engineer only £150-350

Parts commonly replaced

  • Printed Circuit Board (PCB)
  • Internal fuse
  • Wiring harness

Related codes

Full explanation for E97
E99

Your boiler has completely stopped working and locked itself out for safety reasons due to an internal fault or safety system trigger.

High Engineer only £150-300

Parts commonly replaced

  • Main PCB
  • Pressure sensor
  • Wiring harness

Related codes

Full explanation for E99
L1

Your boiler is struggling to keep the water at the right temperature while you are running a hot tap, causing it to protect itself by switching off.

High Engineer only £120-250

Parts commonly replaced

  • DHW NTC sensor
  • Diverter valve
  • Primary heat exchanger

Related codes

Full explanation for L1
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