Ideal Mexico Super 40ff - 80ff Fault codes & diagnostics

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

Regular Natural Gas 11.7-23.4 kW 1997-2005 Discontinued
GC Numbers 41-392-5641-392-5741-392-5841-392-5941-392-60

Replaced by: Mexico HE

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 3 Low
Just want the most common Ideal Mexico Super 40ff - 80ff 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

E01-505

Your boiler is failing to light the pilot flame, which prevents the main burners from igniting and stops your heating and hot water from working.

High Engineer only £120-250

Parts commonly replaced

  • Pilot burner assembly
  • Pilot injector
  • Thermocouple
Full explanation for E01-505
LED 2 goes OFF

Your boiler is attempting to start and creating a spark, but it is failing to detect a flame and is shutting down for safety.

High Engineer only £120-280

Parts commonly replaced

  • Flame Sensing Electrode
  • Gas Valve
  • Ignition Lead
  • Main PCB
Full explanation for LED 2 goes OFF
LED 2 OFF

Your boiler is failing to light because it isn't receiving enough gas to stay running safely.

High DIY-safe £100-250

What to check first

  1. Ensure your gas stopcock is fully open.
  2. If you have a prepayment meter, check that you have sufficient credit.
  3. Check if other gas appliances, like a cooker, are working to confirm your gas supply is active.

Parts commonly replaced

  • Gas Valve
  • Gas Pressure Regulator
  • Inlet Filter
Full explanation for LED 2 OFF
LED 2 OFF briefly

Your boiler is trying to start the flame but the spark system isn't working correctly, preventing it from firing up.

High Engineer only £120-280

Parts commonly replaced

  • Spark Generator
  • Ignition Electrode
  • Control PCB
Full explanation for LED 2 OFF briefly
LED 2 ON

Your boiler is failing to light the gas flame and has shut itself down for safety.

High DIY-safe £120-350

What to check first

  1. Check that your gas supply is turned on and other gas appliances are working
  2. Press and hold the reset button for several seconds to restart the ignition sequence
  3. Check outside to ensure the white condensate pipe hasn't frozen in cold weather

Parts commonly replaced

  • Ignition Electrode
  • Gas Valve
  • Flame Sensing Probe
  • Printed Circuit Board (PCB)
Full explanation for LED 2 ON
LED 3 lit

Your boiler is trying to start its cycle but has detected an electrical issue that is preventing the internal fan from running safely.

High Engineer only £180-350

Parts commonly replaced

  • Main PCB (Printed Circuit Board)
  • Fan Motor
  • Air Pressure Switch

Related codes

Full explanation for LED 3 lit
LED 4 lit

Your boiler is receiving power correctly, but it has failed to ignite or stay lit, causing it to shut down for safety.

High DIY-safe £120-350

What to check first

  1. Check that your gas supply is turned on at the meter
  2. Press the reset button on the front control panel
  3. Monitor the boiler to see if it fires up or if the light returns

Parts commonly replaced

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

Related codes

Full explanation for LED 4 lit
LED2

Your boiler has stopped working for safety reasons and needs to be reset manually to try and restart the system.

High DIY-safe £100-350

What to check first

  1. Locate the reset button on the control panel
  2. Press the reset button once and release it
  3. Wait up to 5 minutes to see if the boiler fires up and the status lights remain steady

Parts commonly replaced

  • Ignition Electrode
  • Gas Valve
  • PCB (Control Board)

Related codes

Full explanation for LED2
LED3

Your boiler is stuck in its starting sequence because it cannot confirm the fan is working correctly to clear away waste gases.

High Engineer only £150-£350

Parts commonly replaced

  • Fan assembly
  • Air pressure switch
  • Main PCB

Related codes

Full explanation for LED3
LED4

Your boiler is receiving electrical power and is currently functioning normally, as this light is a status indicator rather than a fault.

Low DIY-safe

Related codes

Full explanation for LED4
Loss of system water pressure

Your heating system is losing water through a leak, causing the pressure to drop too low for the boiler to operate safely.

High DIY-safe £100-350

What to check first

  1. Locate the external filling loop (usually a silver braided hose with two small valves).
  2. Slowly open both valves to top up the water until the pressure gauge needle matches the red set point.
  3. Ensure both valves are tightly closed once the pressure is restored.

Parts commonly replaced

  • Automatic Air Vent
  • Expansion Vessel
  • Pressure Relief Valve
  • Filling Loop
Full explanation for Loss of system water pressure
Neon I3

Your boiler has electrical power and is ready to operate as normal; this light is a status indicator rather than a fault.

Low DIY-safe

What to check first

  1. No action required if the boiler is heating correctly
  2. If the boiler is not firing, check that your room thermostat is turned up
  3. Ensure your programmer or timer is set to an 'ON' period
Full explanation for Neon I3
Neon SG1

This light simply shows your boiler is currently trying to light the flame and is a normal part of its operation.

Low DIY-safe

What to check first

  1. No action is required as this is a status indicator rather than a fault code.
  2. Ensure your gas supply is turned on if the light flashes for a long time without the boiler firing.
  3. If the light continues to flash but the boiler fails to light, try resetting the boiler.
Full explanation for Neon SG1