BoilerFaultCodes 77
FLAME DETECTION ERROR
Ideal Icos System Fault codes & diagnostics
11 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
System Natural Gas 15-32 kW 2001-2004 Discontinued
GC Number 41-391-52
Replaced by: Logic System
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Versions & GC numbers
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Severity at a glance
Each cell = one fault code. Hover to identify. 10 High
1 Unrated
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 |
|---|---|---|
| 41-391-52 | icos system m3080 | 2001–2004 |
Appliance names and production years are taken from the UK Product Characteristics Database (the SAP/SEDBUK register). Where a GC number is also printed in this model's own manufacturer manual, both sources were checked to agree.
Just want the most common Ideal Icos System faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes
All 11 documented codes
Tap any card for details
78 Your boiler has successfully lit but the flame has gone out unexpectedly, meaning it cannot stay on to heat your home or water.
Your boiler has successfully lit but the flame has gone out unexpectedly, meaning it cannot stay on to heat your home or water.
Parts commonly replaced
- Flame rectification electrode
- Gas valve
- Ignition lead
Related codes
H 1 Your boiler has detected an issue with the water flow or temperature readings and has safely shut down to prevent damage.
Your boiler has detected an issue with the water flow or temperature readings and has safely shut down to prevent damage.
Parts commonly replaced
- NTC Sensor
- Pump
- PCB
H 4 Your boiler has detected that the water temperature inside the system has risen too high, causing it to shut down for safety.
Your boiler has detected that the water temperature inside the system has risen too high, causing it to shut down for safety.
Parts commonly replaced
- Pump
- Heat exchanger
- NTC thermistor
H E Your boiler has detected a communication conflict between its internal electronic control panels, meaning it cannot currently coordinate its functions safely.
Your boiler has detected a communication conflict between its internal electronic control panels, meaning it cannot currently coordinate its functions safely.
Parts commonly replaced
- Control PCB
- Wiring harness
H F Your boiler has detected an issue with the internal computer software or a internal configuration error that prevents it from operating normally.
Your boiler has detected an issue with the internal computer software or a internal configuration error that prevents it from operating normally.
Parts commonly replaced
- Main PCB
Related codes
H n Your boiler has detected an internal communication error between its main control components and is unable to operate safely.
Your boiler has detected an internal communication error between its main control components and is unable to operate safely.
Parts commonly replaced
- Printed Circuit Board (PCB)
- Wiring harness
L 8 Your boiler has detected an issue with the heat exchanger or its temperature control, and it has stopped working to prevent potential damage.
Your boiler has detected an issue with the heat exchanger or its temperature control, and it has stopped working to prevent potential damage.
Parts commonly replaced
- Heat exchanger
- Temperature sensor
- Wiring harness
Related codes
L A Your boiler has detected a critical internal error that prevents it from starting, and it requires a professional safety check.
Your boiler has detected a critical internal error that prevents it from starting, and it requires a professional safety check.
Parts commonly replaced
- Main PCB
- Wiring harness
- Ignition lead
Related codes
L E Your boiler has detected a communication error between its internal electronic brains, causing it to stop functioning for safety reasons.
Your boiler has detected a communication error between its internal electronic brains, causing it to stop functioning for safety reasons.
Parts commonly replaced
- Main printed circuit board
- Wiring harness
Related codes
L F Your boiler is struggling to keep its flame lit or cannot detect the flame, so it has safely shut itself down to prevent gas from building up.
Your boiler is struggling to keep its flame lit or cannot detect the flame, so it has safely shut itself down to prevent gas from building up.
Parts commonly replaced
- Ignition electrode
- Flame rectification probe
- Gas valve
- PCB