Sime Boiler Fault Codes

1,119 fault codes across 44 Sime boiler models — explained in plain English.

Italian manufacturer, part of the Riello Group. Commercial and domestic boilers.

1,119 fault codes
44 models documented
13 currently sold
31 legacy models

Sime fault codes on this site

We document 1,119 fault codes across 44 Sime models, covering 259 distinct codes. Sime boilers use a mix of numbered codes and light or status indications. Codes for 43 of these models are taken directly from the manufacturer's own service or installation manual.

Models covered: Murelle EV HE Combi, Murelle HE System, Murelle EV HE System, Murelle One HE, Murelle Pro HE Combi, Murelle Pro HE System R, Murelle Pro HE 25 HO, Murelle Pro HE MkII Combi, Murelle Pro HE R MkII System, Murelle Elite HE Combi, Murelle Elite HE 35T System, Murelle Advanced HE Combi, Murelle Advanced HE MkII Combi, Murelle Revolution 30, Murelle HE Regular, Murelle HE 110R, Murelle HE Combi with Cylinder, Format DGT HE Combi, Format DGT HE System, Format HE Combi, Format System HE, Format B Combi, Format C Combi, Brava DGT HE, Brava One HE, Brava Slim HE System, Brava Slim HE Regular, Ecomfort HE Combi, Ecomfort System 25 HE, Ecomfort Plus HE, Ecomfort Plus HE EV Combi, Ecomfort System Plus HE EV, Meridian HE, Dewy 30/130 HE FS, Dewy 30/50 HE WM, Friendly, Planet Super 4 WM, Planet Dewy BFR, Metropolis DGT 25 BF, iQE Comfort 30, Halstead Trio, Giulia Combi 30, Mia 30, iQE Simplicity 20T.

Codes that appear on the most Sime models:
AL 02 AL 05 AL 06 AL 07 AL 08 AL 10
Just want the most common Sime problems?
The top 8 faults across the whole Sime range — causes, DIY checks, repair costs.
Most serious

High-severity Sime fault codes

01
Your boiler has detected that it is overheating and has automatically switched itself off to prevent damage.
Murelle EV HE Combi
 02
Your boiler has stopped working because the water pressure inside the heating system has dropped too low.
Murelle EV HE Combi
 04
Your boiler has lost the ability to monitor the temperature of your hot water supply, meaning it will likely stop producing hot water until the faulty sensor is replaced.
Murelle EV HE Combi
 05
Your boiler has stopped working because it is unable to accurately measure the temperature of the water used for your heating system.
Murelle EV HE Combi
 06
Your boiler has detected a serious internal fault and has automatically shut itself down for safety reasons, meaning you currently have no heating or hot water.
Murelle EV HE Combi
All models

44 Sime boiler models

Murelle EV HE Combi
Combi Discontinued
23 fault codes · 2010-2018
Murelle HE System
System Discontinued
24 fault codes · 2004-2012
Murelle EV HE System
System Discontinued
23 fault codes · 2010-2018
Murelle One HE
Combi
30 fault codes · 2019-present
Murelle Pro HE Combi
Combi Discontinued
27 fault codes · 2012-2020
Murelle Pro HE System R
System
27 fault codes · 2012-present
Murelle Pro HE 25 HO
Heat Only Discontinued
27 fault codes · 2015-2018
Murelle Pro HE MkII Combi
Combi
20 fault codes · 2017 onwards
Murelle Pro HE R MkII System
System
45 fault codes · 2017 onwards
Murelle Elite HE Combi
Combi Discontinued
21 fault codes · 2015 onwards
Murelle Elite HE 35T System
System Discontinued
23 fault codes · 2015 onwards
Murelle Advanced HE Combi
Combi
26 fault codes · 2017 onwards
Murelle Advanced HE MkII Combi
Combi
52 fault codes · 2017 onwards
Murelle Revolution 30
Combi
48 fault codes · 2019-present
Murelle HE Regular
Heat Only Discontinued
34 fault codes · 2006-2016
Murelle HE 110R
Heat Only
6 fault codes · 2010-present
Murelle HE Combi with Cylinder
Combi Discontinued
13 fault codes · 2005-2014
Format DGT HE Combi
Combi Discontinued
10 fault codes · 2010-2018
Format DGT HE System
System Discontinued
10 fault codes · 2010-2018
Format HE Combi
Combi Discontinued
7 fault codes · 2004-2012
Format System HE
System Discontinued
6 fault codes · 2004-2012
Format B Combi
Combi Discontinued
14 fault codes · 1995-2005
Format C Combi
Combi Discontinued
3 fault codes · 1998-2008
Brava DGT HE
Combi Discontinued
9 fault codes · 2012-2018
Brava One HE
Combi
49 fault codes · 2016-present
Brava Slim HE System
System
40 fault codes · 2016-present
Brava Slim HE Regular
Heat Only
40 fault codes · 2016-present
Ecomfort HE Combi
Combi Discontinued
7 fault codes · 2003-2012
Ecomfort System 25 HE
System Discontinued
7 fault codes · 2003-2012
Ecomfort Plus HE
CombiSystem Discontinued
11 fault codes · 2005-2014
Ecomfort Plus HE EV Combi
Combi Discontinued
9 fault codes · 2010-2018
Ecomfort System Plus HE EV
System Discontinued
9 fault codes · 2010-2018
Meridian HE
Combi Discontinued
9 fault codes · 2013-2018
Dewy 30/130 HE FS
Combi Discontinued
78 fault codes · 2004-2014
Dewy 30/50 HE WM
Combi Discontinued
67 fault codes · 2004-2014
Friendly
Combi Discontinued
6 fault codes · 1995-2006
Planet Super 4 WM
Combi Discontinued
24 fault codes · 1996-2006
Planet Dewy BFR
Heat Only Discontinued
23 fault codes · 1995-2008
Metropolis DGT 25 BF
Combi Discontinued
50 fault codes · 2008-2016
iQE Comfort 30
Combi Discontinued
21 fault codes · 2013 onwards
Halstead Trio
Combi Discontinued
47 fault codes · 2000-2010
Giulia Combi 30
Combi
34 fault codes · 2023-present
Mia 30
Combi
52 fault codes · 2022-present
iQE Simplicity 20T
Regular Discontinued
8 fault codes · 2012 onwards
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