How much does it cost to fix Ariston error code B08?

Typical repair cost for the Ariston B08 fault is £120-250 including labour.

B08 Medium

Ariston B08 Fault Code

Q: What does the Ariston B08 fault code mean?

Your boiler is having trouble communicating with its internal timer, which means your scheduled heating programs may not turn on or off as expected.

The Ariston B08 fault code means: your boiler is having trouble communicating with its internal timer, which means your scheduled heating programs may not turn on or off as expected.. It appears on 6 Ariston models in our database.

Technical description: Time Clock

Typical repair cost £120-250 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Ariston models that show the B08 fault code

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

Challenger 80E Repair: £120-250
E-Combi One Repair: £120-250
E-Combi One 30 Repair: £120-250
Euro Combi 30 MFFI Repair: £70-160
Euro Prisma 24 Repair: £75-180
Microsystem 15 Repair: £120-250

Source

Ariston B08 fault code information on this page is sourced and cross-checked against the official Ariston service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026