Sime Murelle HE Combi with Cylinder Fault codes & diagnostics

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

Combi Natural Gas 2005-2014 Discontinued
GC Numbers 47-283-1047-283-11
Download the Sime Murelle HE Combi with Cylinder manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. PDF

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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 8 High
Just want the most common Sime Murelle HE Combi with Cylinder faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 9 documented codes

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ALL 02

Your boiler has stopped working because the water pressure inside the heating system has dropped too low.

High DIY-safe £80-150

What to check first

  1. Locate the filling loop (usually a silver braided hose with one or two valves) underneath the boiler.
  2. Open the valve(s) slowly to allow mains water into the system until the pressure gauge reads between 1.0 and 1.5 bar.
  3. Close the valve(s) tightly to stop the flow of water and check the boiler display to see if the error clears.

Parts commonly replaced

  • Filling loop
  • Pressure relief valve
  • Expansion vessel

Related codes

Full explanation for ALL 02
ALL 03

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

High DIY-safe £90-150

What to check first

  1. Locate a radiator in your home, preferably one upstairs.
  2. Place a cloth or small container under the radiator bleed valve.
  3. Open the bleed valve slightly with a radiator key to let water out until the pressure gauge on the boiler drops to between 1 and 1.5 bar, then close the valve tightly.

Parts commonly replaced

  • Pressure relief valve
  • Pressure sensor
  • Filling loop

Related codes

Full explanation for ALL 03
ALL 05

Your boiler has stopped working because it is unable to accurately measure the temperature of the water used for your heating system.

High Engineer only £120-220

Parts commonly replaced

  • Central heating NTC thermistor
  • Wiring harness

Related codes

Full explanation for ALL 05
ALL 06

Your boiler has detected a safety-related issue and has automatically shut down to prevent damage or dangerous operation.

High Engineer only £120-250

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • PCB

Related codes

Full explanation for ALL 06
ALL 07

Your boiler has detected that it is getting too hot and has automatically shut down to prevent damage or overheating.

High Engineer only £120-250

Parts commonly replaced

  • Safety thermostat
  • Pump
  • Diverter valve
  • System filter

Related codes

Full explanation for ALL 07
ALL 08

Your boiler has failed to light the burner or keep it running, so it has safely shut down to prevent unburnt gas from building up.

High Engineer only £150-300

Parts commonly replaced

  • Ignition electrode
  • Flame rectification probe
  • Gas valve
  • PCB

Related codes

Full explanation for ALL 08
ALL 09

Your boiler is struggling to move water around your heating system, which has caused it to shut down to prevent internal damage.

High Engineer only £150-300

Parts commonly replaced

  • Central heating pump
  • Flow switch
  • System filter

Related codes

Full explanation for ALL 09
ALL 10

Your boiler is struggling to detect the temperature of the water coming from your hot water tap, which means it will likely stop producing hot water until it is fixed.

High Engineer only £120-200

Parts commonly replaced

  • Domestic Hot Water (DHW) NTC Temperature Sensor

Related codes

Full explanation for ALL 10
ALL 14

Your boiler has detected that hot exhaust gases are not escaping correctly, which could pose a safety risk, so it has shut itself down to protect your home.

Emergency Engineer only £150-250

Parts commonly replaced

  • Flue thermostat
  • Flue sensor wiring loom
  • Main PCB

Related codes

Full explanation for ALL 14