Worcester Bosch Greenstar 8000 Life System Fault codes & diagnostics

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

System Natural Gas 30-35 kW 2019-present

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Severity at a glance

Each cell = one fault code. Hover to identify.
2 Emergency 41 High 5 Medium 10 Low

All 58 documented codes

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1-A2

Your boiler has detected an internal issue with its electronic control system that prevents it from starting up safely.

High Engineer only £150-350

Parts commonly replaced

  • Control unit
  • Main PCB
  • Wiring harness
1-d3

Your boiler is displaying a status message meant for solar panel systems, which likely means the control system has a minor software configuration error.

Low DIY-safe £90-180

What to check first

  1. Check if the solar panel system is functioning correctly
  2. Press the reset button on the boiler control panel
  3. Monitor the display to see if the message clears

Parts commonly replaced

  • Control Board
  • Solar Module Interface
1-d4

Your boiler is struggling to communicate with your solar water heating system, which may be affecting how your water is warmed by the sun.

Low Engineer only £120-250

Parts commonly replaced

  • Solar module firmware
  • Solar sensor
  • Wiring harness
1-E1

Your boiler's computer software is reporting a version mismatch or a communication error between its internal electronic systems.

Medium Engineer only £120-250

Parts commonly replaced

  • Main Control Unit (PCB)
  • Wiring Harness

Related codes

1-E2

Your boiler’s internal computer is reporting an issue with its own software settings, which is currently preventing the system from operating correctly.

High Engineer only £150-300

Parts commonly replaced

  • Control module
  • PCB
  • Programmer unit

Related codes

1-E3

Your boiler is having trouble 'reading' its internal settings because a small plug that tells the computer how to operate the system has become loose or faulty.

High Engineer only £120-250

Parts commonly replaced

  • Coding plug
  • Main control board (PCB)

Related codes

1-E4

Your boiler has lost communication with its internal configuration chip, meaning it does not know how to operate correctly.

High Engineer only £150-250

Parts commonly replaced

  • Coding plug
  • Main printed circuit board (PCB)
1-EA

Your boiler's computer is having trouble communicating internally, which is preventing it from starting up correctly.

High Engineer only £150-350

Parts commonly replaced

  • Main Control Board (PCB)
  • Wiring Harness
1-Eb

Your boiler's computer system has detected a mismatch or communication error in its internal software configuration.

High Engineer only £150-300

Parts commonly replaced

  • Main Control Board
  • Display Unit
Showing 11–20 of 58
203

Your boiler is currently idle and functioning perfectly, simply waiting for a request from your thermostat or hot water tap to start heating.

Low DIY-safe

What to check first

  1. Check your thermostat or programmer to ensure a heating or hot water schedule is active
  2. Increase the target temperature on your room thermostat
  3. Ensure your boiler is not set to 'Summer' or 'Hot Water Only' mode if you want heating

Related codes

204

Your boiler has temporarily stopped because it detected that the water inside is significantly hotter than the temperature you have set it to reach.

Medium Engineer only £120-250

Parts commonly replaced

  • NTC Temperature Sensor
  • Primary Heat Exchanger
  • Pump
208

Your boiler has been accidentally switched into a specific testing mode used by engineers to check emissions, which temporarily overrides normal heating and hot water operation.

Medium DIY-safe

What to check first

  1. Locate the menu button on your boiler's control panel
  2. Navigate to the service or maintenance settings
  3. Select the option to deactivate or exit the 'Chimney Sweep' or 'Service' mode
224

Your boiler has detected that it has become too hot and has automatically shut itself down to prevent internal damage.

High Engineer only £150-300

Parts commonly replaced

  • Pump
  • Diverter valve
  • Heat exchanger
  • NTC thermistor

Related codes

227

Your boiler is trying to start but failing to stay lit, which means it cannot produce any heating or hot water for your home.

High Engineer only £150-350

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Flame rectification probe
228

Your boiler has detected an internal error where it thinks a flame is present when it actually isn't, which is a safety lockout preventing the unit from operating.

Emergency Engineer only £150-350

Parts commonly replaced

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

Related codes

305

Your boiler is temporarily pausing to prevent the water from overheating, which is a normal protective feature and not a sign of a breakdown.

Low Engineer only
306

Your boiler has detected that the flame is not turning off correctly when it should, which is a safety concern that requires an expert to inspect.

Emergency Engineer only £150-350

Parts commonly replaced

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

Related codes

Showing 21–30 of 58
360

Your boiler's computer chip is not communicating correctly with the main control board, which is preventing the system from starting up safely.

High Engineer only £150-250

Parts commonly replaced

  • Coding plug
  • Main control board
815

Your boiler is struggling to accurately read the temperature of the water circulating through your heating system, which may prevent it from heating your home correctly.

Medium Engineer only £150-250

Parts commonly replaced

  • Low loss header temperature sensor
  • Wiring harness
1010

Your boiler has lost the digital connection between its main parts, meaning it cannot process instructions to heat your home or water.

High Engineer only £150-300

Parts commonly replaced

  • EMS-Bus cable
  • PCB (Main control board)
  • Wiring harness
1017

Your boiler has stopped working because the water pressure inside the heating system has dropped below the required level.

High DIY-safe £0-£120

What to check first

  1. Locate the internal filling link (a silver lever or rotating valve) under the bottom of your boiler.
  2. Open the valve slowly to allow water into the system until the pressure gauge on the front display reaches between 1.0 and 1.5 bar.
  3. Close the valve tightly and check that the fault code clears from the display.

Parts commonly replaced

  • Filling link
  • Pressure sensor
  • Expansion vessel

Related codes

1018

Your boiler is simply reminding you that it is time for its regular annual service to ensure it continues to operate safely and efficiently.

Low Engineer only £90-140
1021

Your boiler is struggling to accurately measure the temperature of the water it is heating, so it has safely shut down to prevent overheating.

High Engineer only £120-200

Parts commonly replaced

  • NTC Temperature Sensor
  • Wiring harness

Related codes

1022

Your boiler is struggling to accurately measure the temperature of your stored hot water, so it has safely stopped heating the tank to prevent overheating.

Medium Engineer only £150-250

Parts commonly replaced

  • NTC Temperature Sensor
  • Sensor Wiring Harness

Related codes

1037

Your boiler is temporarily unable to detect the temperature outside, so it will continue to provide heating and hot water by assuming a standard outdoor temperature.

Low Engineer only £120-200

Parts commonly replaced

  • Outside temperature sensor
1065

Your boiler is unable to read the water pressure level because the sensor responsible for checking it is faulty or has a loose connection.

High Engineer only £150-250

Parts commonly replaced

  • Pressure sensor
  • Wiring harness
1068

Your boiler is struggling because it has lost the signal from the sensor that measures how cold it is outside, meaning it cannot automatically adjust your heating based on the weather.

Low Engineer only £120-220

Parts commonly replaced

  • Outside temperature sensor
  • Wiring harness
Showing 31–40 of 58
1073

Your boiler has lost the ability to accurately measure the temperature of the water flowing through the system due to a faulty electrical connection.

High Engineer only £150-250

Parts commonly replaced

  • NTC Flow Temperature Sensor
  • Wiring Harness

Related codes

1074

Your boiler has lost its connection to the component that monitors how hot the water inside the system is, so it has stopped working as a safety measure.

High Engineer only £150-250

Parts commonly replaced

  • Flow temperature sensor
  • Wiring harness
  • Main control board

Related codes

1075

Your boiler has detected a faulty electrical signal from its internal temperature monitoring system, causing it to shut down for safety to prevent overheating.

High Engineer only £150-250

Parts commonly replaced

  • NTC temperature sensor
  • Wiring harness

Related codes

1076

Your boiler has lost communication with a key temperature sensor, causing it to shut down for safety because it cannot correctly monitor heat levels.

High Engineer only £150-250

Parts commonly replaced

  • NTC Temperature Sensor
  • Wiring harness
  • Main control board (PCB)
2920

Your boiler is struggling to confirm that the burner has safely lit, causing it to shut down to prevent the release of unburnt gas.

High Engineer only £150-300

Parts commonly replaced

  • Ionisation electrode
  • Ignition lead
  • Printed Circuit Board (PCB)

Related codes

2924

Your boiler has detected an internal communication error with the mechanism that controls the gas supply, meaning it is unable to start safely.

High Engineer only £250-450

Parts commonly replaced

  • Gas valve
  • Printed Circuit Board (PCB)

Related codes

2925

Your boiler is struggling to detect the correct flow of gas needed to fire up and heat your home safely.

High Engineer only £250-450

Parts commonly replaced

  • Gas valve
  • Wiring harness
  • Printed Circuit Board (PCB)

Related codes

2927

Your boiler has stopped because the flame inside went out while it was trying to heat your water or home.

High Engineer only £150-300

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Ionisation probe
  • PCB

Related codes

2946

Your boiler's internal computer chip is not being recognised correctly, which is preventing it from starting up safely.

High Engineer only £150-250

Parts commonly replaced

  • Code Plug
  • Printed Circuit Board (PCB)

Related codes

2946 V

Your boiler's computer is struggling to identify the specific configuration chip meant for your model, causing it to shut down for safety.

High Engineer only £150-250

Parts commonly replaced

  • Coding plug
  • PCB

Related codes

Showing 41–50 of 58
2948

Your boiler is failing to stay safely lit because it cannot reliably detect the flame needed to heat your water.

High Engineer only £150-300

Parts commonly replaced

  • Ionisation electrode
  • Ignition lead
  • Main PCB
2948 B

Your boiler has failed to stay lit because it cannot maintain a stable flame at the lowest power setting.

High Engineer only £180-350

Parts commonly replaced

  • Ionisation electrode
  • Gas valve
  • Main PCB

Related codes

2950

Your boiler is trying to start up but it cannot detect a flame, so it has safely shut itself down to prevent gas from building up.

High Engineer only £150-350

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Flame rectification probe

Related codes

2950 B

Your boiler is trying to ignite but cannot detect a flame, meaning it is currently unable to provide heating or hot water for safety reasons.

High Engineer only £150-350

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • PCB

Related codes

2963

Your boiler has detected an unreliable temperature reading from its internal sensors and has shut down as a precaution to prevent damage.

High Engineer only £180-350

Parts commonly replaced

  • NTC Temperature Sensor
  • Wiring Harness
  • Main Control Board

Related codes

2963 B

Your boiler has detected that the temperature reading from its internal pipes is incorrect, so it has safely shut down to prevent potential overheating.

High Engineer only £150-250

Parts commonly replaced

  • NTC temperature sensor harness
  • Flow/Return temperature sensor

Related codes

2964

Your boiler is struggling to pump water around your heating system efficiently, likely due to a blockage in the unit or a problem with the internal pump.

High Engineer only £180-350

Parts commonly replaced

  • Central heating pump
  • Plate heat exchanger
  • Diverter valve

Related codes

2964 B

Your boiler is struggling to circulate water properly, which means it cannot safely heat your home or water.

High Engineer only £180-350

Parts commonly replaced

  • Central Heating Pump
  • Flow Sensor
  • Flow/Return Sensor

Related codes

2965

Your boiler has detected that the water temperature inside the system has become dangerously hot and has shut itself down to prevent damage or overheating.

High Engineer only £150-300

Parts commonly replaced

  • NTC temperature sensor
  • Pump
  • Heat exchanger

Related codes

2965 B

Your boiler is overheating because water isn't circulating through your radiators properly, likely due to low pressure or an issue with the internal pump.

High DIY-safe £120-£250

What to check first

  1. Check your boiler pressure gauge; if it is below 1 bar, use the internal filling link or external filling loop to top the system up to between 1 and 1.5 bar.
  2. Walk around your home and ensure that all your radiator valves are fully open and not stuck shut.
  3. Restart your boiler using the reset button or power cycle to see if the pump clears its blockage.

Parts commonly replaced

  • Circulation pump
  • System filter
  • Diverter valve

Related codes

Showing 51–58 of 58
2966

Your boiler is struggling to move water around effectively, causing it to overheat very quickly because the heat isn't being transferred into your radiators or water properly.

High Engineer only £150-350

Parts commonly replaced

  • Central heating pump
  • Diverter valve
  • Heat exchanger

Related codes

2966 B

Your boiler is shutting down because it cannot circulate water through your heating system, likely due to low pressure or a blockage.

High DIY-safe £120-£250

What to check first

  1. Check your boiler pressure gauge to ensure it is between 1 and 1.5 bar
  2. If the pressure is low, use the external or internal filling loop to top the system up
  3. Ensure all radiator valves and any isolation valves near the boiler are fully open

Parts commonly replaced

  • Circulation pump
  • Heat exchanger
  • Diverter valve

Related codes

2967

Your boiler has detected that water is heating up or cooling down at two different spots in a way that suggests a circulation problem or a faulty reading, so it has stopped working to prevent potential damage.

High Engineer only £150-300

Parts commonly replaced

  • NTC Temperature sensors
  • Central heating pump
  • Plate heat exchanger

Related codes

2967 B

Your boiler has detected that water isn't moving through the unit as expected, likely due to a circulation issue or a sensor that is no longer properly attached.

High Engineer only £150-300

Parts commonly replaced

  • Flow temperature sensor
  • Central heating pump
  • Heat exchanger clip

Related codes

2970

Your boiler has detected a fast leak in your radiator system, meaning it has lost water pressure too quickly for it to operate safely.

High DIY-safe £120-250

What to check first

  1. Check all radiators, valves, and exposed pipework for signs of wet patches or dripping water.
  2. Inspect the pressure relief pipe exiting through an external wall to see if it is leaking water outdoors.
  3. If no visible leaks are found, use the external filling loop to top the boiler pressure back up to 1.5 bar.

Parts commonly replaced

  • Pressure relief valve
  • Expansion vessel
  • Filling loop

Related codes

2970 B

Your boiler has detected that the water pressure in your heating system is falling away much faster than it should, causing it to shut down to protect itself.

High DIY-safe £120-250

What to check first

  1. Check your radiators and pipework throughout the house for any visible signs of water leaks or wet patches on the floor.
  2. Locate the external filling loop or internal key usually found underneath the boiler and open the valve slowly to reach the recommended pressure of 1.5 bar on the gauge.
  3. Monitor the pressure gauge over the next few hours to see if it drops again, which would confirm a persistent leak requiring a professional.

Parts commonly replaced

  • Pressure relief valve
  • Expansion vessel
  • Filling loop valve

Related codes

2971

Your boiler has stopped working because the water pressure inside the heating system has dropped too low.

High DIY-safe £0-£120

What to check first

  1. Locate the internal filling link or external filling loop beneath the boiler.
  2. Open the valves slowly to allow mains water into the system until the pressure gauge reads between 1.0 and 1.5 bar.
  3. Close the valves firmly and check that the fault code has cleared.

Parts commonly replaced

  • Filling loop
  • Pressure sensor
  • Expansion vessel

Related codes

2971 B

Your boiler has stopped working because the water pressure inside your heating system has dropped below the required level.

High DIY-safe £80-120

What to check first

  1. Locate the internal or external filling loop connected to your boiler pipes
  2. Slowly open the valves to allow mains water to enter the system until the pressure gauge reads between 1.5 and 2 bar
  3. Close both valves tightly and ensure the pressure gauge remains stable

Parts commonly replaced

  • Filling link
  • Pressure relief valve
  • Pressure sensor

Related codes