Medium
t1 on Worcester Bosch Greenstar CDi Compact

Your boiler is currently trying to light its internal pilot flame and will continue making a clicking sound for up to 30 seconds to get the process started.

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

Igniter test. Checking the igniter spark. The igniter will spark for a maximum of 30 seconds. The spark will be audible if the igniter is OK.

From this model's manual
Verified against the Worcester Bosch Greenstar Cdi Compact 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.

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 t1: 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

EAView →F7View →

Related guides you might find useful

Pilot light keeps going out

Older boilers — thermocouple, draught, gas supply.

Read →

Boiler keeps cutting out

Lockout fault with a reset-needed pattern.

Read →

Yellow or orange flame — CO safety

Safety-critical — turn off, read this.

Read →