Medium
B08 on Ariston Euro Combi 30 MFFI

Your boiler's built-in timer or clock has encountered a communication error, meaning the heating may not turn on at your scheduled times.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

What the manual says

Manufacturer manual

Time Clock

From this model's manual
Verified against the Ariston Euro Combi 30 Mffi installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Check the clock settings to ensure they haven't been accidentally clearedRotate the timer pins or digital settings to 'On' to see if the boiler firesPerform a simple reset of the boiler using the 'R' or reset button

Find a Gas Safe engineer
Search the official register →
Boiler cover options

Avoid the next call-out bill

A cover plan would handle faults like B08: no call-out fees, no surprise bills.

Approved partner
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Get a quote →

Affiliate links. We may earn a commission at no extra cost to you.

Related fault codes

B07View →

Related guides you might find useful

Yellow or orange flame — CO safety

Safety-critical — turn off, read this.

Read →

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →