How much does it cost to fix Sime error code 3 bar?

Typical repair cost for the Sime 3 bar fault is £80-150 including labour.

3 bar High

Sime 3 bar Fault Code

Q: What does the Sime 3 bar fault code mean?

Your boiler's internal water pressure is too high, which can cause it to leak or shut down to protect itself from damage.

Also written as 3BAR — same fault.

The Sime 3 bar fault code means: your boiler's internal water pressure is too high, which can cause it to leak or shut down to protect itself from damage.. It appears on 1 Sime model in our database.

Technical description: 108 - 113 Ω

Typical repair cost £80-150 (including labour)

DIY fix possible

Locate a radiator in your home that is easy to access.Place a cloth or small container under the radiator bleed valve.Open the bleed valve slightly to release air and a small amount of water until the pressure gauge on the boiler drops to between 1 and 1.5 bar, then close the valve tightly.

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Sime models that show the 3 bar fault code

Click a model for the full fault code list and model-specific repair notes.

Dewy 30/50 HE WM Repair: £80-150

Source

Sime 3 bar fault code information on this page is sourced and cross-checked against the official Sime service / installation manuals for each affected model.

Sime Dewy 30/50 HE WM manual (PDF)

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026