Low water pressure in system
Sime Murelle Advanced HE MkII Combi Fault codes & diagnostics
52 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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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 |
|---|---|---|
| 47-283-82 | MURELLE ADVANCED HE 30 MkII | 2017–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.
All 52 documented codes
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High water pressure in system
Domestic hot water sensor (SS) fault
Delivery sensor (SM) fault
no flame detected
Safety thermostat (TS), intervention
Fault in the flame detection circuit
No water circulating in the system
Auxiliary sensor fault
Gas valve modulator disconnected
Incorrect configuration of the open / sealed chamber
Exhaust sensor (SF) intervention
Exhaust sensor (SF) fault
Fan check cable disconnected
Condensate level fault
Maximum number of consecutive resets reached (6)
Fault due to low network voltage
Incorrect supply frequency detected
Flame loss more than 6 consecutive times
Button fault
Open Therm communication fault
Self-calibrating procedure is required
Incorrect positioning of the delivery sensor
Block due to combustion during start-up
Irregular combustion (temporary error)
Lockout due to flue (exhaust) blockage
ALL 02 Your boiler has stopped working because the water pressure inside the heating system has dropped below the minimum level required to operate safely.
Your boiler has stopped working because the water pressure inside the heating system has dropped below the minimum level required to operate safely.
What to check first
- Locate the external filling loop (a flexible silver hose) underneath the boiler.
- Open the small tap or valve on the filling loop to allow cold mains 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 the tap or valve tightly to stop the flow of water.
Parts commonly replaced
- Pressure relief valve
- Expansion vessel
- Pressure sensor
Related codes
ALL 03 Your boiler has detected that there is too much water inside the heating system, causing the pressure to rise above the safe limit.
Your boiler has detected that there is too much water inside the heating system, causing the pressure to rise above the safe limit.
What to check first
- Locate a radiator in your home that has a bleed valve.
- Place a cloth and a container under the valve.
- Open the valve slightly with a radiator key to let water out until the pressure gauge on the boiler drops back into the green zone (usually 1.0 to 1.5 bar).
- Close the valve tightly.
Parts commonly replaced
- Pressure relief valve
- Pressure transducer
Related codes
ALL 04 Your boiler is struggling to detect the temperature of the hot water it produces, which will likely stop your taps and shower from getting warm.
Your boiler is struggling to detect the temperature of the hot water it produces, which will likely stop your taps and shower from getting warm.
Parts commonly replaced
- DHW Temperature Sensor (NTC)
- Wiring harness
Related codes
ALL 05 Your boiler has stopped working because it is unable to accurately measure the temperature of the water inside the system.
Your boiler has stopped working because it is unable to accurately measure the temperature of the water inside the system.
Parts commonly replaced
- Delivery NTC sensor
- Wiring harness
Related codes
ALL 06 Your boiler is failing to ignite because it cannot detect the burner flame, meaning you currently have no heating or hot water.
Your boiler is failing to ignite because it cannot detect the burner flame, meaning you currently have no heating or hot water.
Parts commonly replaced
- Flame rectification electrode
- Ignition lead
- Gas valve
- PCB
Related codes
ALL 07 Your boiler has detected that it has become dangerously overheated and has automatically shut itself down to prevent damage.
Your boiler has detected that it has become dangerously overheated 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 has detected that the burner is not staying lit, so it has shut itself down as a safety precaution.
Your boiler has detected that the burner is not staying lit, so it has shut itself down as a safety precaution.
Parts commonly replaced
- Ignition electrode
- Flame rectification probe
- PCB
Related codes
ALL 09 Your boiler has detected that water is not moving through your heating system correctly, which is preventing it from heating your home or water.
Your boiler has detected that water is not moving through your heating system correctly, which is preventing it from heating your home or water.
Parts commonly replaced
- Circulation pump
- Flow sensor
- System filter
Related codes
ALL 10 Your boiler's computer is struggling to read a temperature sensor, which has caused it to stop working to ensure your safety.
Your boiler's computer is struggling to read a temperature sensor, which has caused it to stop working to ensure your safety.
Parts commonly replaced
- NTC Sensor
- Wiring harness
Related codes
ALL 11 Your boiler has lost the electrical connection to the valve that controls the gas supply, meaning it cannot safely start up to provide heat or hot water.
Your boiler has lost the electrical connection to the valve that controls the gas supply, meaning it cannot safely start up to provide heat or hot water.
Parts commonly replaced
- Gas valve assembly
- Wiring harness
Related codes
ALL 12 Your boiler has lost its correct settings for how it handles air intake and exhaust, which means it has safely stopped working to prevent incorrect operation.
Your boiler has lost its correct settings for how it handles air intake and exhaust, which means it has safely stopped working to prevent incorrect operation.
Parts commonly replaced
- Main PCB
Related codes
ALL 13 Your boiler has detected that the flue gases are getting too hot, so it has automatically shut down to prevent damage to the internal components.
Your boiler has detected that the flue gases are getting too hot, so it has automatically shut down to prevent damage to the internal components.
Parts commonly replaced
- Exhaust temperature sensor
- Primary heat exchanger
- PCB
Related codes
ALL 14 Your boiler has detected an issue with the sensor that monitors the temperature of the exhaust fumes, causing it to stop operating to ensure safety.
Your boiler has detected an issue with the sensor that monitors the temperature of the exhaust fumes, causing it to stop operating to ensure safety.
Parts commonly replaced
- Flue gas temperature sensor
- Wiring harness
- PCB
Related codes
ALL 15 Your boiler has stopped working because the connection between its internal fan and the main control board has been lost or interrupted.
Your boiler has stopped working because the connection between its internal fan and the main control board has been lost or interrupted.
Parts commonly replaced
- Fan wiring harness
- Fan assembly
- Main PCB
Related codes
ALL 18 Your boiler has detected that waste water cannot drain away properly, so it has shut down to prevent internal flooding.
Your boiler has detected that waste water cannot drain away properly, so it has shut down to prevent internal flooding.
Parts commonly replaced
- Condensate trap
- Condensate pipework
- Siphon
Related codes
ALL 28 Your boiler has blocked itself because it has been reset too many times in a row without the original underlying problem being solved.
Your boiler has blocked itself because it has been reset too many times in a row without the original underlying problem being solved.
Parts commonly replaced
- Main PCB
- Ignition electrode
- Gas valve
Related codes
ALL 37 Your boiler has detected that the electricity supply coming from your home's wall socket or fuse spur is lower than it needs to be to operate safely.
Your boiler has detected that the electricity supply coming from your home's wall socket or fuse spur is lower than it needs to be to operate safely.
Parts commonly replaced
- External power supply
- Boiler PCB
Related codes
ALL 40 Your boiler has detected that the electricity supply coming from your home's mains is unstable or at the wrong frequency, preventing it from starting safely.
Your boiler has detected that the electricity supply coming from your home's mains is unstable or at the wrong frequency, preventing it from starting safely.
Parts commonly replaced
- Printed Circuit Board (PCB)
- Power supply cabling
Related codes
ALL 41 Your boiler is repeatedly failing to keep its internal flame lit, so it has stopped working to keep you safe.
Your boiler is repeatedly failing to keep its internal flame lit, so it has stopped working to keep you safe.
Parts commonly replaced
- Ignition electrode
- Gas valve
- Flame rectification probe
Related codes
ALL 42 Your boiler's control panel is registering that one of the buttons is permanently stuck or faulty, which is preventing the system from operating normally.
Your boiler's control panel is registering that one of the buttons is permanently stuck or faulty, which is preventing the system from operating normally.
Parts commonly replaced
- User interface control panel
- PCB board
Related codes
ALL 43 Your boiler's internal computer has lost its connection to the external controller, meaning it cannot receive signals to turn your heating or hot water on.
Your boiler's internal computer has lost its connection to the external controller, meaning it cannot receive signals to turn your heating or hot water on.
Parts commonly replaced
- OpenTherm interface cable
- PCB (Printed Circuit Board)
- External thermostat/controller
Related codes
ALL 62 Your boiler has lost its internal settings and needs a professional software calibration to communicate correctly with its internal components.
Your boiler has lost its internal settings and needs a professional software calibration to communicate correctly with its internal components.
Related codes
ALL 72 Your boiler is struggling to read the temperature of the water flowing out of it because the sensor that monitors this is loose or incorrectly fitted.
Your boiler is struggling to read the temperature of the water flowing out of it because the sensor that monitors this is loose or incorrectly fitted.
Parts commonly replaced
- Flow temperature sensor
- Sensor wiring harness
Related codes
ALL 81 Your boiler has detected an issue with the burning process during startup and has safely shut itself down to prevent any unsafe operation.
Your boiler has detected an issue with the burning process during startup and has safely shut itself down to prevent any unsafe operation.
Parts commonly replaced
- Ignition electrode
- Gas valve
- Flame sensor
Related codes
ALL 83 Your boiler has detected that it is struggling to burn the gas cleanly and has temporarily paused its operation to prevent any build-up of fumes.
Your boiler has detected that it is struggling to burn the gas cleanly and has temporarily paused its operation to prevent any build-up of fumes.
Parts commonly replaced
- Flue seal
- Gas valve
- Spark electrode
- Burner assembly
Related codes
ALL 96 Your boiler has detected an obstruction in the flue pipe that expels exhaust gases, so it has shut itself down to prevent carbon monoxide buildup.
Your boiler has detected an obstruction in the flue pipe that expels exhaust gases, so it has shut itself down to prevent carbon monoxide buildup.
Parts commonly replaced
- Flue terminal
- Venturi
- Fan assembly
- Air pressure switch
Related codes
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