High
A04 on Euroterm E27 Plus

Your boiler has shut down because it detected a recurring problem with how exhaust gases are being cleared from the system.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

Flue gas fault. Possible cause: Fault F07 happened 3 times in the last 24 hours.

Community-sourced, unverified
We could not tie this code to a specific manual. Treat it as indicative only.
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 high 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 A04: 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

F07View →

All 38 fault codes on the E27 Plus

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

A01A02A03A05A06A09A16A21A23A24A41A42A44A61A62A63A64A65F04F05F07F10F11F12F13F14F15F20F34F35F37F39F42F43F47F52F66

Related guides you might find useful

Boiler keeps losing pressure

Six most common causes of dropping pressure.

Read →

Banging / kettling / whistling noise

Each noise points to a different fault.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →