Medium
164 229 on Ariston Excalibur

Your boiler has detected a physical seal failure, likely causing a small water leak inside the appliance casing that needs to be addressed to prevent damage to internal electrical components.

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

Gasket 1/2"

Shared across the Excalibur range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

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

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 164 229: 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.

All 21 fault codes on the Excalibur

Seeing a different code? Every code this model can display, in one place.

164 225164 261164 282Anti-frost deviceE25 425E61 468E61 483E61 485E61 490E61 520E61 547E61 565E61 567E61 569E61 665E61 667Ignition FailureInsufficient CirculationInsufficient System PressureOverheating

Related guides you might find useful

Boiler leaking water

Turn it off first. Where the water comes from tells you which part has gone.

Read →

Boiler keeps losing pressure

Six most common causes of dropping pressure.

Read →

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →