Ferroli Bluehelix Tech RRT Fault codes & diagnostics

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

Combi Natural Gas 2018-present
GC Numbers 47-267-7147-267-72
Download the Ferroli Bluehelix Tech RRT manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. PDF

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Severity at a glance

Each cell = one fault code. Hover to identify.
3 Emergency 40 High 1 Low
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
47-267-71 BLUEHELIX TECH RRT 24C 2018–present
47-267-72 BLUEHELIX TECH RRT 28C 2018–present
Just want the most common Ferroli Bluehelix Tech RRT faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 44 documented codes

Tap any card for details

A01

Your boiler is failing to light the gas flame, meaning you have no hot water or heating.

High DIY-safe £90-£350

What to check first

  1. Check if other gas appliances in your home are working to ensure gas is being supplied.
  2. Press the 'Reset' button on the boiler control panel to clear the temporary error.
  3. Ensure your pre-payment gas meter has sufficient credit.

Parts commonly replaced

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

Related codes

Full explanation for A01
A02

Your boiler detects a flame when it shouldn't be burning, which acts as a safety lockout to prevent any danger.

High Engineer only £120-280

Parts commonly replaced

  • Ionisation Electrode
  • Control PCB
  • Gas Valve

Related codes

Full explanation for A02
A05

Your boiler has stopped working because the internal fan, which safely exhausts waste gases, has failed to start or is spinning at the wrong speed.

High Engineer only £220-£450

Parts commonly replaced

  • Extraction fan
  • Wiring harness
  • Main PCB

Related codes

Full explanation for A05
A06

Your boiler is failing to stay alight after it tries to start up, meaning it cannot provide heat or hot water.

High DIY-safe £100-280

What to check first

  1. Check that your gas supply is turned on at the meter
  2. Check if other gas appliances in your home are working
  3. Press the 'Reset' button on the boiler control panel

Parts commonly replaced

  • Ignition Electrode
  • Gas Valve
  • Ionisation Lead

Related codes

Full explanation for A06
A07

Your boiler has detected that the exhaust gases leaving the system are dangerously hot, so it has automatically shut itself down to prevent damage.

Emergency Engineer only £150-300

Parts commonly replaced

  • Primary heat exchanger
  • Flue sensor
  • Temperature sensor

Related codes

Full explanation for A07
A08

Your boiler has sensed that the water inside is getting too hot and has shut itself down to prevent damage.

High DIY-safe £120-280

What to check first

  1. Check that all radiator valves are fully open to allow water to circulate.
  2. Ensure there is enough pressure in the system by checking the gauge (it should be between 1 and 1.5 bar).
  3. Try resetting the boiler by pressing the 'Reset' button.

Parts commonly replaced

  • Overheat Thermostat
  • Circulation Pump
  • Flow Temperature Sensor

Related codes

Full explanation for A08
A09

Your boiler has sensed that the water returning to the unit is too hot, causing it to shut down for safety.

High DIY-safe £120-£350

What to check first

  1. Check that at least two or three radiator valves are fully open
  2. Ensure the central heating system pressure is between 1.0 and 1.5 bar
  3. Press the reset button on the boiler control panel

Parts commonly replaced

  • Return temperature sensor (NTC)
  • Circulation pump
  • Secondary heat exchanger

Related codes

Full explanation for A09
A10

Your boiler's internal sensor that monitors water movement has stopped working properly, preventing the system from heating up correctly.

High Engineer only £130-£220

Parts commonly replaced

  • Flow temperature sensor (NTC)
  • Sensor wiring harness

Related codes

Full explanation for A10
A13

Your boiler has detected an issue with the sensor that monitors exhaust gases, and it has shut down as a safety precaution.

High Engineer only £120-190

Parts commonly replaced

  • Flue gas probe
  • Wiring harness

Related codes

Full explanation for A13
A14

Your boiler has shut down because it has detected a blockage or a safety issue with the way exhaust fumes are being cleared from the flue pipe.

Emergency Engineer only £100-280

Parts commonly replaced

  • Flue pressure switch
  • Fan assembly
  • Flue seals
  • Condensate trap

Related codes

Full explanation for A14
Showing 11–20 of 44
A23

Your boiler's computer brain has become confused by its own internal settings and is unable to operate correctly.

High Engineer only £180-350

Parts commonly replaced

  • Main PCB (Control Board)
  • External Parameter Memory Card

Related codes

Full explanation for A23
A24

Your boiler's internal computer has encountered a settings error and cannot function correctly until it is reprogrammed or replaced.

High Engineer only £120-450

Parts commonly replaced

  • Printed Circuit Board (PCB)
  • Control Interface

Related codes

Full explanation for A24
A26

Your boiler's internal computer has encountered a configuration error and cannot communicate correctly with its sensors.

High Engineer only £280-450

Parts commonly replaced

  • Main PCB (Control Board)
  • External Sensor

Related codes

Full explanation for A26
A42

Your boiler has shut down because a temperature sensor has detected a reading that is inconsistent or out of its safe operating range.

High Engineer only £120-220

Parts commonly replaced

  • CH temperature sensor (NTC)
  • DHW temperature sensor
  • Wiring harness

Related codes

Full explanation for A42
A54

Your boiler's internal computer has encountered a critical communication error and can no longer control the heating system safely.

High Engineer only £250-£450

Parts commonly replaced

  • Main PCB (AGC01 Board)
  • Wiring Harness

Related codes

Full explanation for A54
A55

Your boiler's main control board has encountered an internal electronic error and needs to be inspected by a professional.

High Engineer only £250-450

Parts commonly replaced

  • Main PCB (AGC01 Board)
  • Wiring Harness

Related codes

Full explanation for A55
A56

Your boiler has failed to correctly set up its internal combustion settings, meaning it cannot run efficiently or safely and has shut down.

High Engineer only £120-350

Parts commonly replaced

  • Electrode
  • Integrated Gas Valve
  • Main PCB

Related codes

Full explanation for A56
A61

Your boiler's internal computer is experiencing a communication or hardware error, which prevents it from safely operating your heating and hot water.

High Engineer only £250-450

Parts commonly replaced

  • Main Control PCB

Related codes

Full explanation for A61
A63

Your boiler's internal computer has developed a technical communication error, preventing the system from running safely.

High Engineer only £280-£450

Parts commonly replaced

  • Main PCB (Printed Circuit Board)
  • Wiring Harness

Related codes

Full explanation for A63
A64

Your boiler has locked itself for safety because the reset button has been pressed too many times in a short period to clear a recurring fault.

High Engineer only £100-£350

Parts commonly replaced

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

Related codes

Full explanation for A64
Showing 21–30 of 44
A68

Your boiler has encountered an internal communication error with its configuration data key, preventing it from operating correctly.

High Engineer only £120-280

Parts commonly replaced

  • BCC (Boiler Chip Card)
  • PCB (Main Control Board)

Related codes

Full explanation for A68
F08

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

High Engineer only £120-250

Parts commonly replaced

  • NTC sensor
  • Circulation pump
  • Heat exchanger

Related codes

Full explanation for F08
F10

Your boiler is struggling to detect the flow of water through the system, which means it has stopped providing heating or hot water to keep components safe.

High Engineer only £150-250

Parts commonly replaced

  • Flow sensor
  • Wiring harness

Related codes

Full explanation for F10
F12

Your boiler has lost the ability to measure the temperature of the water used for your taps and shower, so it has stopped providing hot water to ensure safety.

High Engineer only £120-220

Parts commonly replaced

  • DHW NTC sensor
  • Wiring harness

Related codes

Full explanation for F12
F13

Your boiler has detected an issue with the sensor that monitors the temperature of the gases leaving your flue, meaning it has safely shut down to prevent incorrect operation.

High Engineer only £120-220

Parts commonly replaced

  • Flue gas temperature sensor
  • Wiring harness

Related codes

Full explanation for F13
F14

Your boiler has detected that the exhaust gases are becoming dangerously hot, so it has shut itself down to prevent internal damage.

Emergency Engineer only £150-300

Parts commonly replaced

  • Flue gas sensor
  • Heat exchanger
  • Pump

Related codes

Full explanation for F14
F15

Your boiler's internal computer has encountered a configuration error and can no longer communicate correctly with the system.

High Engineer only £180-450

Parts commonly replaced

  • Main PCB (Printed Circuit Board)
  • Display Interface

Related codes

Full explanation for F15
F20

Your boiler's internal computer has encountered a configuration error and can no longer process its instructions correctly.

High Engineer only £120-450

Parts commonly replaced

  • Main PCB (Printed Circuit Board)
  • Ignition Electrode

Related codes

Full explanation for F20
F21

Your boiler's internal computer has encountered a configuration error and cannot communicate correctly with the system settings.

High DIY-safe £180-450

What to check first

  1. Switch off the electrical power to the boiler for 30 seconds
  2. Turn the power back on and wait for the system to re-initialise
  3. If the code persists, press the Reset button on the control panel

Parts commonly replaced

  • Printed Circuit Board (PCB)
  • Main Control Panel

Related codes

Full explanation for F21
F34

Your boiler has stopped working because the electricity supply from the mains or to the internal components has dropped too low to operate safely.

High Engineer only £100-£350

Parts commonly replaced

  • Printed Circuit Board (PCB)
  • Low voltage Transformer

Related codes

Full explanation for F34
Showing 31–40 of 44
F37

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

High DIY-safe £0-120

What to check first

  1. Locate the filling loop (the flexible silver hose) underneath or near the boiler.
  2. Open the small black taps on the filling loop slowly until you hear water entering the system.
  3. Watch the pressure gauge on the boiler display and close the taps once it reaches 1.5 bar.

Parts commonly replaced

  • Filling loop valve
  • Pressure sensor
  • Expansion vessel re-pressurisation

Related codes

Full explanation for F37
F39

Your boiler has lost communication with the outdoor temperature sensor, meaning it may struggle to regulate your heating efficiently.

Low Engineer only £90-160

Parts commonly replaced

  • External temperature probe
  • Connecting wiring / terminal block

Related codes

Full explanation for F39
F40

Your boiler's internal computer has encountered a configuration error or memory fault and cannot operate properly.

High Engineer only £180-450

Parts commonly replaced

  • Main PCB
  • Parameter Key/Configuration Chip

Related codes

Full explanation for F40
F42

Your boiler has detected that its temperature sensors are giving conflicting readings or have changed too rapidly, causing it to shut down for safety.

High DIY-safe £120-250

What to check first

  1. Check that your home's central heating valves and radiator valves are fully open
  2. Check that the boiler pressure is between 1 and 1.5 bar on the gauge
  3. Turn the boiler off and on again to see if the fault clears

Parts commonly replaced

  • CH temperature sensor (NTC thermistor)
  • Heat exchanger sensor
  • Circulation pump

Related codes

Full explanation for F42
F43

Your boiler has shut down because the internal heat exchanger is getting too hot, usually caused by poor water circulation or trapped air.

High DIY-safe £100-350

What to check first

  1. Check that your system water pressure is between 1.0 and 1.5 bar on the pressure gauge.
  2. Ensure all radiator valves are fully open to allow water to flow through the system.
  3. Gently bleed your radiators to remove any trapped air that could be blocking circulation.

Parts commonly replaced

  • Circulation pump
  • Heat exchanger (descaling)
  • System filter (cleaning)

Related codes

Full explanation for F43
F47

Your boiler’s internal computer has encountered a settings error and cannot function properly until the control board is reconfigured or replaced.

High Engineer only £180-£450

Parts commonly replaced

  • Main PCB (Control Board)
  • PCB Configuration Plug

Related codes

Full explanation for F47
F50

Your boiler's computer brain has become confused or lost its internal settings, preventing it from running safely.

High Engineer only £250-450

Parts commonly replaced

  • Main PCB (Printed Circuit Board)
  • Parameter Memory Key

Related codes

Full explanation for F50
F51

Your boiler is having trouble managing its internal combustion settings, which means the system cannot guarantee safe or efficient operation and has shut down.

High Engineer only £120-350

Parts commonly replaced

  • Ionisation electrode
  • Gas valve
  • Main PCB

Related codes

Full explanation for F51
F53

Your boiler is having trouble controlling the balance of gas and air needed for a steady flame and has shut down as a safety precaution.

High Engineer only £120-350

Parts commonly replaced

  • Gas valve
  • Flame sensing electrode
  • Main PCB

Related codes

Full explanation for F53
F56

Your boiler's control system has failed to correctly adjust the gas and air mixture required for safe and efficient combustion.

High Engineer only £120-450

Parts commonly replaced

  • Gas valve
  • Flame sensing electrode
  • Main PCB

Related codes

Full explanation for F56
Showing 41–44 of 44
F61

Your boiler has failed to complete its necessary internal self-tuning process, preventing it from running efficiently or safely.

High DIY-safe £100-350

What to check first

  1. Locate the reset button on the control panel
  2. Press and hold the reset button for 5 seconds
  3. Wait for the boiler to attempt the automatic calibration cycle

Parts commonly replaced

  • Gas valve
  • Ionisation electrode
  • PCB (Control board)

Related codes

Full explanation for F61
F66

Your boiler's internal computer software has failed to load, meaning the system cannot operate your heating or hot water.

High Engineer only £150-300

Parts commonly replaced

  • Main control board (PCB)
  • Firmware update module

Related codes

Full explanation for F66
F67

Your boiler has detected that a service programming tool is plugged into its computer brain, which is preventing the system from running normally.

High Engineer only £90-180

Parts commonly replaced

  • BCC Plug
  • Main Control PCB

Related codes

Full explanation for F67
F68

Your boiler's main control board is having trouble communicating with its internal security and identity chip.

High Engineer only £120-380

Parts commonly replaced

  • BCC (Boiler Chip Card)
  • PCB (Main Control Board)

Related codes

Full explanation for F68
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