Emergency
F7 on Worcester Bosch Highflow 250

Your boiler has detected a flame signal even though it is not supposed to be running, which is a serious safety concern as it suggests the gas valve may not be closing properly.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

What the manual says

Manufacturer manual

Flame seen although burner switched off

Shared across the 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 is a emergency severity fault. Stop using the boiler and call 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 F7: 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 →

All 57 fault codes on the Highflow 250

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

6A6C6d9UA1A4A5A7A8ACAdB1b2b3b4b5b6b7C1C4C6D1d3d5d6E2E5E9EAF0F1FAFdH1H4H7H9HCHeatbank Overheat StatHot water high limit statNo codeoverheat lock-out statePOINT BPOINT CPOINT DPOINT EPOINT FPOINT GPOINT HPOINT IPOINT JPOINT KPOINT NS9Safety limit statSy

Related guides you might find useful

Pilot light keeps going out

Older boilers — thermocouple, draught, gas supply.

Read →

Yellow or orange flame — CO safety

Safety-critical — turn off, read this.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →