High
E:02.20 on Baxi 400 424 / 428 Combi

Your boiler's internal computer has detected a change in its configuration settings, which is preventing it from starting up correctly.

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

Jumper 2 changed

Shared across the 400 424 / 428 Combi 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 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 E:02.20: 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

E:02.21View →E:02.22View →

All 41 fault codes on the 400 424 / 428 Combi

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

E:00.04E:00.05E:01.04E:01.11E:01.12E:01.17E:01.20E:02.00E:02.07E:02.16E:02.17E:02.19E:02.21E:02.47E:02.48E:04.00E:04.01E:04.02E:04.03E:04.04E:04.05E:04.06E:04.08E:04.10E:04.12E:04.13E:04.17H:01 .00H:01 .05H:01 .08H:01 .14H:01 .18H:01.21H:02.02H:02.03H:02.04H:02.06H:03.00H:03.01H:03.02

Related guides you might find useful

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →

Boiler service cost

What a UK service costs and what a proper one includes.

Read →