Ideal Excel HE C24 Fault codes & diagnostics

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

Combi Natural Gas 2004-2009 Discontinued
GC Number 47-348-35
Download the Ideal Excel HE C24 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.
1 Emergency 7 High

All 8 documented codes

Tap any card for details

ERROR CODE 1

Your boiler has temporarily stopped working because it tried to start up several times but could not detect a flame.

High Engineer only £90-250

Parts commonly replaced

  • Ignition lead
  • Spark electrode
  • Gas valve

Related codes

ERROR CODE 2

Your boiler has detected that it is running too hot and has automatically shut down to prevent damage to its internal parts.

High Engineer only £150-300

Parts commonly replaced

  • Pump
  • Heat exchanger
  • Overheat thermostat
  • Diverter valve
ERROR CODE 3

Your boiler has detected an issue with the water pressure or the flow regulation system, causing it to shut down to prevent damage.

High Engineer only £150-250

Parts commonly replaced

  • Water Pressure Switch
  • Pump
  • Diverter Valve
ERROR CODE 4

Your boiler has detected an issue with its internal airflow or ventilation system, preventing it from safely starting up.

High Engineer only £150-300

Parts commonly replaced

  • Air Pressure Switch
  • Fan Assembly
  • Venturi
ERROR CODE 5

Your boiler's temperature sensor is providing incorrect readings, so it has shut down to prevent the water from getting too hot.

High Engineer only £120-200

Parts commonly replaced

  • Central Heating NTC Thermistor
  • Wiring harness
ERROR CODE 6

Your boiler is currently unable to sense the temperature of your hot water tap supply, which means it has stopped heating water to prevent the system from getting too hot.

High Engineer only £120-200

Parts commonly replaced

  • DHW NTC Thermistor
ERROR CODE 7

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

Emergency Engineer only £150-300

Parts commonly replaced

  • Flue gas temperature sensor
  • Primary heat exchanger
  • PCB
ERROR CODE 8

Your boiler is unable to drain away the water it creates during normal operation, causing it to block up and stop working to prevent internal damage.

High DIY-safe £80-150

What to check first

  1. Locate the plastic condensate pipe exiting your home, usually found outside near the wall.
  2. Check for any visible blockages like frozen ice, leaves, or debris at the end of the pipe.
  3. If frozen, pour warm (not boiling) water over the pipe to melt the ice, then press the boiler's reset button.

Parts commonly replaced

  • Condensate trap
  • Condensate pipework
  • Siphon