Ferroli Hawk II Fault codes & diagnostics

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

Combi Natural Gas 24-28 kW 2013-2018 Discontinued

Replaced by: Bluehelix Tech

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.
10 High 1 Medium 2 Low
Just want the most common Ferroli Hawk II faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 13 documented codes

Tap any card for details

LED 1

Your boiler is currently completely unresponsive because it is not receiving any power, which might be due to a tripped switch, a disconnected plug, or a blown internal fuse.

High DIY-safe £90-180

What to check first

  1. Check your home's central fuse box to ensure the boiler circuit breaker hasn't tripped.
  2. Verify the fused spur switch located near the boiler is turned to the ON position.
  3. Inspect the plug or connection point to ensure it is secure and the external fuse has not blown.

Parts commonly replaced

  • Main printed circuit board (PCB)
  • Internal fuse
  • Power supply cable
Full explanation for LED 1
LED 2 (A)

Your boiler is failing to detect that you have turned on a hot water tap, meaning it won't fire up to heat the water.

Medium Engineer only £120-220

Parts commonly replaced

  • DHW Flow Sensor
  • Flowmeter turbine
Full explanation for LED 2 (A)
LED 2 (B)

Your boiler correctly detects that a hot water tap is currently running, so it is firing up to provide you with hot water.

Low Engineer only

Parts commonly replaced

  • DHW Flow switch
  • PCB
Full explanation for LED 2 (B)
LED 3 (B)

Your boiler is currently idle because it is not receiving a signal from your thermostat or timer to start heating.

High DIY-safe £90-180

What to check first

  1. Check that your wall thermostat is set to a temperature higher than the current room temperature.
  2. Ensure your timer or programmer is set to an 'ON' period.
  3. Replace the batteries in your wireless room thermostat if it uses them.
  4. Check if any smart heating app linked to your boiler says the system is in 'Off' or 'Away' mode.

Parts commonly replaced

  • External room thermostat
  • Programmer/Timer
  • Wiring centre
Full explanation for LED 3 (B)
LED 4 (A)

Your boiler has stopped providing hot water because it is struggling to read or regulate the temperature from its water heating sensor.

High Engineer only £120-220

Parts commonly replaced

  • DHW NTC thermistor sensor
  • Wiring loom
Full explanation for LED 4 (A)
LED 4 (B)

Your boiler has stopped working because it cannot properly read the water temperature or it has detected that it is running too hot.

High Engineer only £120-200

Parts commonly replaced

  • Central heating sensor (NTC)
  • Limit thermostat
Full explanation for LED 4 (B)
LED 5 (A)

Your boiler's electronic brain is malfunctioning and cannot correctly process its startup sequence, meaning it will currently fail to provide heating or hot water.

High Engineer only £250-450

Parts commonly replaced

  • Printed Circuit Board (PCB)
Full explanation for LED 5 (A)
LED 6 (A)

Your boiler has stopped working because it is unable to accurately detect the water pressure or temperature, preventing it from safely heating your home or water.

High Engineer only £120-250

Parts commonly replaced

  • DHW NTC sensor
  • Pressure switch
  • Limit thermostat
Full explanation for LED 6 (A)
LED 6 (B)

Your boiler has stopped working because it has detected an issue with its internal temperature sensors or water pressure levels, preventing it from safely heating your home.

High Engineer only £120-250

Parts commonly replaced

  • Central Heating Temperature Sensor
  • Limit Thermostat
  • Pressure Switch
Full explanation for LED 6 (B)
LED 7

Your boiler has detected an issue with the internal ventilation system that removes exhaust gases, so it has safely disabled itself to prevent any risk.

High Engineer only £150-250

Parts commonly replaced

  • Flue fan
  • Air pressure switch
  • Venturi
Full explanation for LED 7
RY2

Your boiler has stopped working because the connection to the control system is failing to receive the necessary electrical power.

High Engineer only £150-300

Parts commonly replaced

  • PCB
  • Wiring harness
Full explanation for RY2
RY4

Your boiler is failing to start because it cannot confirm that the internal fan is operating correctly, preventing the safe clearing of exhaust gases.

High Engineer only £120-250

Parts commonly replaced

  • Air pressure switch
  • Fan assembly
  • PCB
Full explanation for RY4