Sime Murelle Advanced HE MkII Combi Fault codes & diagnostics

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

Combi Natural Gas 2017 onwards
GC Number 47-283-82
Download the Sime Murelle Advanced HE MkII Combi manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. PDF

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Severity at a glance

Each cell = one fault code. Hover to identify.
2 Emergency 22 High 2 Medium

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
47-283-82 MURELLE ADVANCED HE 30 MkII 2017–present

All 26 documented codes

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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.

High DIY-safe

What to check first

  1. Locate the external filling loop (a flexible silver hose) underneath the boiler.
  2. Open the small tap or valve on the filling loop to allow cold mains water into the system.
  3. Watch the pressure gauge on the front of the boiler until the needle reaches the green zone (typically 1.0 to 1.5 bar).
  4. 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.

Medium DIY-safe £0-120

What to check first

  1. Locate a radiator in your home that has a bleed valve.
  2. Place a cloth and a container under the valve.
  3. 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).
  4. 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.

Medium Engineer only £120-180

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.

High Engineer only £120-200

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.

High Engineer only £120-250

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.

High Engineer only £120-250

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.

High Engineer only £120-250

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.

High Engineer only £150-350

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.

High Engineer only £150-250

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.

High Engineer only £120-220

Parts commonly replaced

  • Gas valve assembly
  • Wiring harness

Related codes

Showing 11–20 of 26
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.

High Engineer only £120-200

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.

High Engineer only £150-300

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.

High Engineer only £120-220

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.

High Engineer only £120-200

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.

High Engineer only £100-200

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.

High Engineer only £120-250

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.

High Engineer only £100-200

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.

High Engineer only £120-250

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.

High Engineer only £150-300

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.

High Engineer only £150-250

Parts commonly replaced

  • User interface control panel
  • PCB board

Related codes

Showing 21–26 of 26
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.

High Engineer only £120-250

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.

High Engineer only £90-160
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.

High Engineer only £120-220

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.

Emergency Engineer only £120-250

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.

High Engineer only £120-250

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.

Emergency Engineer only £120-250

Parts commonly replaced

  • Flue terminal
  • Venturi
  • Fan assembly
  • Air pressure switch

Related codes

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