Ideal Excel HE Fault codes & diagnostics

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

Combi Natural Gas 24-32 kW 2004-2009 Discontinued
GC Numbers 47-348-3547-348-3647-348-37

Replaced by: Logic HE

Download the Ideal Excel HE manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. 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 11 High
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
47-348-35 excel HE C24 2004–2009
47-348-36 excel HE C28 2004–2009
47-348-37 excel HE C32 2004–2009
Just want the most common Ideal Excel HE faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 12 documented codes

Tap any card for details

Automatic Shutdown

Your boiler has stopped working because the pipe that drains away waste water is blocked, either by frozen water or a build-up of debris.

High DIY-safe £80-150

What to check first

  1. Locate the white plastic condensate pipe leading outside from your boiler.
  2. If it is winter, pour warm (not boiling) water over the external section of the pipe to thaw any ice.
  3. Ensure the end of the pipe is not submerged in standing water or blocked by debris.

Parts commonly replaced

  • Condensate trap
  • Condensate pipework
  • Siphon
Full explanation for Automatic Shutdown
ERROR CODE 1

Your boiler has stopped working for safety reasons and needs to be restarted, but if it keeps happening, an internal fault is preventing it from firing up.

High Engineer only £120-250

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Printed circuit board (PCB)
Full explanation for ERROR CODE 1
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
Full explanation for ERROR CODE 2
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
Full explanation for ERROR CODE 3
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
Full explanation for ERROR CODE 4
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
Full explanation for ERROR CODE 5
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
Full explanation for ERROR CODE 6
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
Full explanation for ERROR CODE 7
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
Full explanation for ERROR CODE 8
Ignition Lockout

Your boiler is trying to start but cannot detect a flame, likely because it is not receiving any gas.

High Engineer only £120-250

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Printed Circuit Board (PCB)
Full explanation for Ignition Lockout
Overheat condition

Your boiler has detected that it is running too hot and has automatically turned itself off to prevent internal damage.

High Engineer only £150-300

Parts commonly replaced

  • Pump
  • Heat exchanger
  • NTC thermistor
Full explanation for Overheat condition
Red operational light 2 (E)

Your boiler has failed to ignite and has safely locked itself down to prevent any issues with unburnt gas.

High Engineer only £150-300

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Spark generator
Full explanation for Red operational light 2 (E)