Sime Murelle Elite HE 35T System Fault codes & diagnostics

21 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 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.
1 Emergency 14 High 5 Medium 1 Low
Versions & GC numbers

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
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 21 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.

High DIY-safe £80-120

What to check first

  1. Locate the external filling loop (a silver braided hose) underneath the boiler.
  2. Open the valves at both ends of the hose to allow 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 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

Full explanation for ALL 02
ALL 03

Your boiler has detected that the water pressure inside your heating system is currently set too high for it to operate safely.

High DIY-safe £80-150

What to check first

  1. Locate a radiator in your home, preferably one upstairs.
  2. Using a radiator bleed key, carefully open the bleed valve to let a small amount of water out into a cloth or container.
  3. 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

Full explanation for ALL 03
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.

High Engineer only £120-220

Parts commonly replaced

  • DHW NTC sensor
  • Wiring harness

Related codes

Full explanation for ALL 04
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.

High Engineer only £120-220

Parts commonly replaced

  • Central heating NTC sensor
  • Wiring harness

Related codes

Full explanation for ALL 05
ALL 06

Your boiler has detected an internal safety fault and has stopped operating to prevent further damage.

High Engineer only £150-300

Parts commonly replaced

  • Main printed circuit board (PCB)
  • Wiring harness
  • Ignition transformer

Related codes

Full explanation for ALL 06
ALL 07

Your boiler has detected that it is dangerously overheating and has automatically shut itself down to prevent damage.

High Engineer only £150-300

Parts commonly replaced

  • Safety thermostat
  • Pump
  • Diverter valve
  • Primary heat exchanger

Related codes

Full explanation for ALL 07
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.

High Engineer only £120-250

Parts commonly replaced

  • Flame rectification electrode
  • Ignition lead
  • Printed Circuit Board (PCB)

Related codes

Full explanation for ALL 08
ALL 09

Your boiler is struggling to move water through your heating system, which is preventing it from heating your home properly.

High Engineer only £150-300

Parts commonly replaced

  • Circulation pump
  • Flow sensor
  • System filter

Related codes

Full explanation for ALL 09
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.

High Engineer only £120-220

Parts commonly replaced

  • External temperature sensor
  • Wiring harness
  • PCB

Related codes

Full explanation for ALL 10
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.

Emergency Engineer only £150-250

Parts commonly replaced

  • Flue gas sensor
  • Wiring harness
  • PCB

Related codes

Full explanation for ALL 14
Showing 11–20 of 21
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.

High Engineer only £180-350

Parts commonly replaced

  • Flue fan assembly
  • Wiring harness
  • PCB

Related codes

Full explanation for ALL 15
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.

High Engineer only £150-300

Parts commonly replaced

  • High limit thermostat
  • Circulation pump
  • System zone valve

Related codes

Full explanation for ALL 20
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.

Medium Engineer only £120-200

Parts commonly replaced

  • NTC Temperature Sensor
  • Wiring harness

Related codes

Full explanation for ALL 21
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.

High Engineer only £120-250

Parts commonly replaced

  • Safety thermostat
  • Pump for second mixed zone
  • Mixing valve
  • NTC sensor

Related codes

Full explanation for ALL 22
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.

Medium Engineer only £120-250

Parts commonly replaced

  • External zone controller
  • Mixed zone sensor
  • Wiring harness

Related codes

Full explanation for ALL 23
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.

Medium Engineer only £150-250

Parts commonly replaced

  • Solar collector temperature sensor
  • Wiring harness

Related codes

Full explanation for ALL 24
ALL 25

Your boiler is having trouble communicating with the solar water heating sensor, which may prevent it from using solar-heated water correctly.

Medium Engineer only £120-220

Parts commonly replaced

  • Solar probe sensor
  • Wiring harness

Related codes

Full explanation for ALL 25
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.

Low Engineer only £120-200

Parts commonly replaced

  • Solar NTC probe
  • Wiring harness

Related codes

Full explanation for ALL 26
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.

Medium Engineer only £120-250

Parts commonly replaced

  • Main PCB
  • Solar interface module

Related codes

Full explanation for ALL 27
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.

High Engineer only £150-350

Parts commonly replaced

  • Main PCB
  • Wiring harness

Related codes

Full explanation for ALL 28
Showing 21–21 of 21
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.

High Engineer only £150-350

Parts commonly replaced

  • Main PCB
  • Wiring harness

Related codes

Full explanation for ALL 29