BoilerFaultCodes ALL 01
FLUE TEMPERATURE ALARM
Sime Murelle Elite HE 35T System Fault codes & diagnostics
23 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
System Natural Gas 2015 onwards Discontinued
GC Numbers 41-283-4341-283-54
Download the Sime Murelle Elite HE 35T System manual
PDF
Versions & GC numbers
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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
14 High
5 Medium
1 Low
2 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 |
|---|---|---|
| 41-283-54 | Murelle Elite HE 35 T ErP | 2015–present |
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 Sime Murelle Elite HE 35T System faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes
All 23 documented codes
Tap any card for details
ALL 02 Your boiler has stopped working because the water pressure inside your heating system has dropped too low.
Your boiler has stopped working because the water pressure inside your heating system has dropped too low.
What to check first
- Locate the external filling loop (a silver braided hose) underneath the boiler.
- Open the valves at both ends of the hose to allow water into the system.
- Watch the pressure gauge on the front of the boiler until the needle reaches the green zone (typically 1.0 to 1.5 bar).
- Close both valves firmly and ensure the hose is disconnected if required by your specific installation.
Parts commonly replaced
- Filling loop
- Pressure relief valve
- Pressure sensor
Related codes
ALL 03 Your boiler has detected that the water pressure inside your heating system is currently set too high for it to operate safely.
Your boiler has detected that the water pressure inside your heating system is currently set too high for it to operate safely.
What to check first
- Locate a radiator in your home, preferably one upstairs.
- Using a radiator bleed key, carefully open the bleed valve to let a small amount of water out into a cloth or container.
- Monitor the pressure gauge on your boiler front panel until it returns to the green zone (typically 1.0 to 1.5 bar), then stop bleeding.
Parts commonly replaced
- Pressure relief valve
- Pressure sensor
Related codes
ALL 04 Your boiler is struggling to detect the temperature of the water used for your taps and showers, so it has stopped providing hot water to prevent any potential damage.
Your boiler is struggling to detect the temperature of the water used for your taps and showers, so it has stopped providing hot water to prevent any potential damage.
Parts commonly replaced
- DHW NTC sensor
- Wiring harness
Related codes
ALL 05 Your boiler has detected an issue with the sensor that measures the temperature of the water used for your radiators, meaning it has safely shut itself down to prevent overheating.
Your boiler has detected an issue with the sensor that measures the temperature of the water used for your radiators, meaning it has safely shut itself down to prevent overheating.
Parts commonly replaced
- Central heating NTC sensor
- Wiring harness
Related codes
ALL 06 Your boiler has detected an internal safety fault and has stopped operating to prevent further damage.
Your boiler has detected an internal safety fault and has stopped operating to prevent further damage.
Parts commonly replaced
- Main printed circuit board (PCB)
- Wiring harness
- Ignition transformer
Related codes
ALL 07 Your boiler has detected that it is dangerously overheating and has automatically shut itself down to prevent damage.
Your boiler has detected that it is dangerously overheating and has automatically shut itself down to prevent damage.
Parts commonly replaced
- Safety thermostat
- Pump
- Diverter valve
- Primary heat exchanger
Related codes
ALL 08 Your boiler is failing to detect a flame, which means it cannot safely light or stay running to provide you with heating or hot water.
Your boiler is failing to detect a flame, which means it cannot safely light or stay running to provide you with heating or hot water.
Parts commonly replaced
- Flame rectification electrode
- Ignition lead
- Printed Circuit Board (PCB)
Related codes
ALL 09 Your boiler is struggling to move water through your heating system, which is preventing it from heating your home properly.
Your boiler is struggling to move water through your heating system, which is preventing it from heating your home properly.
Parts commonly replaced
- Circulation pump
- Flow sensor
- System filter
Related codes
ALL 10 Your boiler's control system is struggling to read a secondary temperature sensor, which has caused it to stop working to ensure your safety.
Your boiler's control system is struggling to read a secondary temperature sensor, which has caused it to stop working to ensure your safety.
Parts commonly replaced
- External temperature sensor
- Wiring harness
- PCB
Related codes
Showing 11–20 of 23
ALL 13
ACTIVATION OF THE EXHAUST FUMES SENSOR ERROR
ALL 14 Your boiler has detected an issue with the sensor that monitors exhaust gases and has shut itself down to keep your home safe.
Your boiler has detected an issue with the sensor that monitors exhaust gases and has shut itself down to keep your home safe.
Parts commonly replaced
- Flue gas sensor
- Wiring harness
- PCB
Related codes
ALL 15 Your boiler has detected that the internal fan is not spinning as it should, so it has safely shut down to prevent unsafe operation.
Your boiler has detected that the internal fan is not spinning as it should, so it has safely shut down to prevent unsafe operation.
Parts commonly replaced
- Flue fan assembly
- Wiring harness
- PCB
Related codes
ALL 20 Your boiler has detected that the water temperature in one of your heating circuits has become dangerously high and has automatically shut down to prevent damage.
Your boiler has detected that the water temperature in one of your heating circuits has become dangerously high and has automatically shut down to prevent damage.
Parts commonly replaced
- High limit thermostat
- Circulation pump
- System zone valve
Related codes
ALL 21 Your boiler is having trouble reading the temperature for one of your heating zones, which may stop that specific area from warming up properly.
Your boiler is having trouble reading the temperature for one of your heating zones, which may stop that specific area from warming up properly.
Parts commonly replaced
- NTC Temperature Sensor
- Wiring harness
Related codes
ALL 22 Your boiler has detected that the water temperature in one of your heating circuits has become dangerously high, so it has automatically shut down to prevent damage.
Your boiler has detected that the water temperature in one of your heating circuits has become dangerously high, so it has automatically shut down to prevent damage.
Parts commonly replaced
- Safety thermostat
- Pump for second mixed zone
- Mixing valve
- NTC sensor
Related codes
ALL 23 Your boiler is having trouble communicating with the secondary heating zone in your home, which means that specific area may not be receiving heat as expected.
Your boiler is having trouble communicating with the secondary heating zone in your home, which means that specific area may not be receiving heat as expected.
Parts commonly replaced
- External zone controller
- Mixed zone sensor
- Wiring harness
Related codes
ALL 24 Your boiler is struggling to read the temperature from the solar panel unit on your roof, which is preventing the solar-assisted heating system from operating correctly.
Your boiler is struggling to read the temperature from the solar panel unit on your roof, which is preventing the solar-assisted heating system from operating correctly.
Parts commonly replaced
- Solar collector temperature sensor
- Wiring harness
Related codes
ALL 25 Your boiler is having trouble communicating with the solar water heating sensor, which may prevent it from using solar-heated water correctly.
Your boiler is having trouble communicating with the solar water heating sensor, which may prevent it from using solar-heated water correctly.
Parts commonly replaced
- Solar probe sensor
- Wiring harness
Related codes
ALL 26 Your boiler's temperature sensor responsible for reading your solar water heating system is not working correctly, which may prevent your solar panels from contributing to your hot water supply.
Your boiler's temperature sensor responsible for reading your solar water heating system is not working correctly, which may prevent your solar panels from contributing to your hot water supply.
Parts commonly replaced
- Solar NTC probe
- Wiring harness
Related codes
Showing 21–23 of 23
ALL 27 Your boiler has detected an issue with how the settings are configured for a solar heating add-on, preventing it from operating correctly.
Your boiler has detected an issue with how the settings are configured for a solar heating add-on, preventing it from operating correctly.
Parts commonly replaced
- Main PCB
- Solar interface module
Related codes
ALL 28 Your boiler has detected an issue with how its internal settings are communicating, likely due to a configuration error or a faulty circuit board connection.
Your boiler has detected an issue with how its internal settings are communicating, likely due to a configuration error or a faulty circuit board connection.
Parts commonly replaced
- Main PCB
- Wiring harness
Related codes
ALL 29 Your boiler's internal computer is struggling to communicate with its own internal components, meaning it has shut down as a safety precaution.
Your boiler's internal computer is struggling to communicate with its own internal components, meaning it has shut down as a safety precaution.
Parts commonly replaced
- Main PCB
- Wiring harness