Alpha 240E / 280E Fault codes & diagnostics

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

Combi Natural Gas Discontinued
Choose your boiler type

The 240E / 280E range comes in 2 types

Pick the one you have. The fault codes, GC numbers and manual differ by type.

240E 14 codes · 2 GC numbers 280E 14 codes · 2 GC numbers
Each model has its own manual A family spans several manuals, one per model or generation. Pick your model above and its page has the manual its fault codes were read from.

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.
5 High 2 Medium
Just want the most common Alpha 240E / 280E faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 7 documented codes

Tap any card for details

Fan runs at max. speed

Your boiler's fan is running continuously at full speed, which indicates the system has detected a safety concern and is trying to clear the air inside the unit.

High Engineer only £150-300 Shared across the 240E / 280E range

Parts commonly replaced

  • Air pressure switch
  • Flue sampling tube
  • Printed circuit board (PCB)
Full explanation for Fan runs at max. speed
neon illuminated

Your boiler has developed an internal electrical fault, meaning the control board is likely failing and unable to safely operate the system.

High Engineer only £200-350 Shared across the 240E / 280E range

Parts commonly replaced

  • Neon PCB
  • Main PCB
Full explanation for neon illuminated
Primary flow switch operated

Your boiler detects water movement even when it is not supposed to, which often means an internal valve is stuck or a sensor is misreading the flow.

Medium Engineer only £120-220 Shared across the 240E / 280E range

Parts commonly replaced

  • Flow switch
  • Diverter valve diaphragm
Full explanation for Primary flow switch operated
Pump circulating water / No

Your boiler is struggling to push water around your radiators and taps, likely because there is trapped air in the system or the internal water pump has become faulty.

High Engineer only £250-450 Shared across the 240E / 280E range

Parts commonly replaced

  • Central heating pump
  • Automatic air vent
Full explanation for Pump circulating water / No
Pump runs

Your boiler's water pump is running constantly, which suggests the unit is stuck in a cycle trying to clear air or respond to a faulty thermostat signal.

Medium Engineer only £120-250 Shared across the 240E / 280E range

Parts commonly replaced

  • PCB
  • Flow switch
  • Pump relay
Full explanation for Pump runs
Red reset button illuminated

Your boiler has stopped working because it failed to ignite, but you can attempt to restart it by pressing the red reset button.

High DIY-safe £120-250 Shared across the 240E / 280E range

What to check first

  1. Check that your gas supply is turned on and other gas appliances like your hob are working.
  2. Ensure your gas prepayment meter has credit if applicable.
  3. Locate the red reset button on the control panel, press it once firmly, and wait for the boiler to attempt an ignition sequence.

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Printed Circuit Board (PCB)
Full explanation for Red reset button illuminated
Spark at ignition electrodes

Your boiler is struggling to light its internal flame, which means it cannot produce the heat or hot water you need.

High Engineer only £120-250 Shared across the 240E / 280E range

Parts commonly replaced

  • Ignition electrode
  • Ignition lead
  • PCB (Printed Circuit Board)
  • Gas valve
Full explanation for Spark at ignition electrodes
Status & diagnostic codes

1 operating states & engineer diagnostics

Not faults — these are normal operating states. Tap to expand.

Burner output modulates Status Your boiler is automatically adjusting its flame intensity to save energy and balance heat, which is a normal part of its efficient operation rather than a breakdown.