Ferroli Pro RRT 30S Fault codes & diagnostics

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

System Natural Gas
GC Number 41-267-51
Download the Ferroli Pro RRT 30S manualThe official installation and service manual (PDF), the document these fault codes were read from. PDF

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.
2 Emergency 44 High 1 Medium 2 Low

All 49 documented codes

Tap any card for details

A02

Your boiler has detected that a flame is present even though it has commanded the burner to turn off, which is a significant safety protection fault.

Emergency Engineer only £150-300

Parts commonly replaced

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

Related codes

A05

Your boiler is unable to safely vent exhaust gases because the internal fan that pushes air through the system has stopped working correctly.

High Engineer only £180-350

Parts commonly replaced

  • Fan assembly
  • Wiring harness
  • PCB

Related codes

A06

Your boiler is attempting to start but failing to light the burner, meaning it cannot produce heat or hot water.

High Engineer only £150-300

Parts commonly replaced

  • Ignition electrode
  • Flame rectification probe
  • Gas valve

Related codes

A07

Your boiler has detected that the exhaust gases leaving the unit are getting too hot, so it has shut itself down to prevent damage to internal parts.

High Engineer only £150-350

Parts commonly replaced

  • Primary heat exchanger
  • Flue gas temperature sensor
  • Burner assembly

Related codes

A08

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

High Engineer only £120-250

Parts commonly replaced

  • NTC temperature sensor
  • System pump
  • Heat exchanger

Related codes

A09

Your boiler has detected that it is getting dangerously hot and has shut itself down to prevent damage.

High Engineer only £150-350

Parts commonly replaced

  • System filter
  • Central heating pump
  • Heat exchanger
  • NTC sensor

Related codes

A10

Your boiler is failing to detect the flow of water through the system, which means it cannot safely start up to provide you with heating or hot water.

High Engineer only £150-250

Parts commonly replaced

  • Flow sensor
  • Wiring harness

Related codes

A11

Your boiler is having trouble 'reading' the temperature of the water returning to it, so it has stopped working as a safety precaution to prevent overheating.

High Engineer only £120-220

Parts commonly replaced

  • Return temperature sensor
  • Wiring harness

Related codes

A13

Your boiler has detected an issue with the sensor that monitors the temperature of the gases leaving your flue, causing it to shut down for safety.

High Engineer only £120-220

Parts commonly replaced

  • Flue gas temperature sensor
  • Wiring harness

Related codes

A14

Your boiler has switched itself off because the safety sensors have detected that harmful exhaust gases are not being cleared safely from the flue pipe.

Emergency Engineer only £120-350

Parts commonly replaced

  • Flue pressure switch
  • Fan assembly
  • Venturi tube

Related codes

Showing 11–20 of 49
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

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

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

A42

Your boiler has detected that the water temperature is rising too quickly or is not being correctly moderated, causing it to shut down for safety.

High Engineer only £150-250

Parts commonly replaced

  • Central heating sensor
  • Return sensor
  • Main PCB

Related codes

A54

Your boiler's internal computer is experiencing a communication or hardware error, which has caused it to stop working for your safety.

High Engineer only £250-400

Parts commonly replaced

  • Main PCB (AGC01)
  • Wiring harness

Related codes

A55

Your boiler's main control computer is experiencing a software or hardware error, which prevents it from operating correctly.

High Engineer only £250-450

Parts commonly replaced

  • Main PCB (AGC01)

Related codes

A56

Your boiler's internal computer is struggling to correctly adjust its gas and air mixture to ensure it burns fuel efficiently.

High Engineer only £120-250

Parts commonly replaced

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

Related codes

A61

Your boiler's main internal computer is failing to communicate properly, which has forced the system to shut down to prevent further damage.

High Engineer only £250-450

Parts commonly replaced

  • Main Control PCB

Related codes

A62

Your boiler has stopped working because the internal control board and the gas valve are no longer communicating with each other.

High Engineer only £180-450

Parts commonly replaced

  • Main PCB
  • Gas Valve
  • Wiring Harness

Related codes

A63

Your boiler’s main computer chip is experiencing an internal error, preventing the system from monitoring or controlling your heating properly.

High Engineer only £250-400

Parts commonly replaced

  • Main Control PCB

Related codes

Showing 21–30 of 49
A64

Your boiler has been manually reset too many times in a short period and has now locked itself out for safety.

High Engineer only £100-350

Parts commonly replaced

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

Related codes

A68

Your boiler's internal computer is struggling to read its configuration settings, which has caused it to stop working for your safety.

High Engineer only £150-300

Parts commonly replaced

  • BCC key
  • Main control board (PCB)

Related codes

F07

Your boiler has detected that the exhaust gases leaving the system are getting too hot, so it has shut down to prevent potential damage or overheating.

High Engineer only £150-350

Parts commonly replaced

  • Flue gas sensor
  • Heat exchanger

Related codes

F08

Your boiler has detected that it is running too hot and has automatically shut itself down to prevent any damage or safety issues.

High Engineer only £120-250

Parts commonly replaced

  • NTC Temperature Sensor
  • Primary Heat Exchanger
  • Pump (Circulator)

Related codes

F09

Your boiler has detected that the water inside it is getting too hot and has automatically shut down to prevent damage or potential overheating.

High Engineer only £120-250

Parts commonly replaced

  • System pressure sensor
  • Central heating pump
  • NTC temperature sensor
  • Primary heat exchanger

Related codes

F10

Your boiler is struggling to detect the flow of water through the system, which means it has stopped providing heating and hot water to protect itself.

High Engineer only £150-250

Parts commonly replaced

  • Flow sensor
  • Wiring loom

Related codes

F11

Your boiler is unable to read the temperature of the water returning to it, so it has safely shut down to prevent overheating.

High Engineer only £120-220

Parts commonly replaced

  • Return NTC sensor
  • Wiring harness

Related codes

F12

Your boiler is having trouble detecting the temperature of the water used for your taps and shower, so it has stopped providing hot water to prevent overheating.

Medium Engineer only £120-180

Parts commonly replaced

  • DHW NTC thermistor

Related codes

F13

Your boiler has detected an issue with the sensor that monitors the temperature of the gases leaving your flue, causing it to shut down for safety reasons.

High Engineer only £120-220

Parts commonly replaced

  • Flue gas sensor
  • Wiring harness

Related codes

F14

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

High Engineer only £150-300

Parts commonly replaced

  • Primary heat exchanger
  • Flue gas temperature sensor
  • Central heating pump

Related codes

Showing 31–40 of 49
F15

Your boiler's computer has detected a configuration error and has safely shut itself down to prevent damage.

High Engineer only £150-300

Parts commonly replaced

  • Main Control PCB
  • Configuration Key

Related codes

F20

Your boiler's internal computer is experiencing a software or configuration error that is preventing it from operating correctly.

High Engineer only £250-450

Parts commonly replaced

  • Control Board (PCB)
  • Configuration card

Related codes

F21

The internal computer in your boiler has identified an error in its configuration settings, causing it to stop运行 safely.

High Engineer only £150-300

Parts commonly replaced

  • Main Control PCB
  • Configuration card

Related codes

F34

Your boiler is receiving an insufficient amount of electricity to operate safely and effectively.

High Engineer only £120-250

Parts commonly replaced

  • Printed Circuit Board (PCB)
  • Power supply wiring
  • Fuse

Related codes

F37

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

High DIY-safe £80-150

What to check first

  1. Locate the external filling loop, which is usually a small metal or braided hose located under the boiler.
  2. Open the small valve(s) on the loop to allow mains water to enter the system until the pressure gauge on the front of the boiler reads between 1.0 and 1.5 bar.
  3. Close the valve(s) tightly and check that the error code has cleared.

Parts commonly replaced

  • Pressure relief valve
  • Expansion vessel
  • Pressure sensor
F39

Your boiler is struggling to read the outdoor temperature, so it is defaulting to a standard internal setting until the sensor is fixed.

Low Engineer only £100-200

Parts commonly replaced

  • External weather compensation sensor
  • Wiring harness

Related codes

F40

The boiler's internal computer has encountered a memory error or configuration mistake that prevents it from starting up correctly.

High Engineer only £150-300

Parts commonly replaced

  • Control Board (PCB)
  • Configuration Plug

Related codes

F41

Your boiler has detected that water is heating up too quickly compared to the sensors' expectations, causing it to shut down to prevent damage.

High Engineer only £120-250

Parts commonly replaced

  • NTC sensor
  • Circulation pump
  • Heat exchanger

Related codes

F42

Your boiler has detected an inconsistent temperature reading between its internal sensors, which has caused it to stop working as a safety precaution to prevent overheating.

High Engineer only £150-250

Parts commonly replaced

  • Dual NTC temperature sensor
  • Wiring harness
  • Printed Circuit Board (PCB)

Related codes

F43

Your boiler has detected that the heat exchanger is getting too hot, so it has purposefully shut down to prevent internal damage.

High Engineer only £180-350

Parts commonly replaced

  • NTC sensor
  • Primary heat exchanger
  • Pump

Related codes

Showing 41–49 of 49
F47

Your boiler's computer system has detected an error in its internal settings, causing it to stop operating to prevent further issues.

High Engineer only £150-300

Parts commonly replaced

  • Main printed circuit board (PCB)
  • Control board

Related codes

F50

Your boiler's internal computer is experiencing a software or configuration error that is preventing it from operating correctly.

High Engineer only £250-450

Parts commonly replaced

  • Main Control PCB
  • Configuration Key

Related codes

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

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

F56

Your boiler has lost the correct settings for its internal combustion process and needs to be professionally reconfigured to run safely and efficiently.

High Engineer only £120-220

Parts commonly replaced

  • Gas Valve
  • PCB

Related codes

F61

Your boiler's internal electronic control center is experiencing a critical communication error and cannot safely operate the heating system.

High Engineer only £250-450

Parts commonly replaced

  • Main PCB (AGC01)
  • Wiring harness
F66

Your boiler's internal computer has failed to start up correctly, which means it cannot operate your heating or hot water systèmes.

High Engineer only £150-300

Parts commonly replaced

  • Main control board (PCB)
  • Wiring harness

Related codes

F67

Your boiler is currently in a setup or diagnostic mode because a programming key has been left plugged into its internal control board.

Low Engineer only £80-120

Parts commonly replaced

  • BCC Service Key

Related codes

F68

Your boiler's internal computer is failing to communicate correctly with its memory chip, which prevents the system from starting up safely.

High Engineer only £150-300

Parts commonly replaced

  • BCC (Boiler Control Configuration) key
  • Main PCB

Related codes

Avoid the next call-out bill

Monthly cover means no unexpected bills when your boiler breaks down.

Approved partner
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Get a quote →

Affiliate links. We may earn a commission at no extra cost to you.