Unknown
E.01.20 on Baxi 430 COMBI 2.1

Baxi 430 COMBI 2.1 fault code E.01.20

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

What the manual says

Manufacturer manual

Maximum flue gas temperature reached

From this model's manual
Verified against the Baxi/Baxi 400 Combi 2 Baxi400 Comni 2 1 Installation Manual Pdf 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 E.01.20: 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.

All 65 fault codes on the 430 COMBI 2.1

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

254A.00.28A.00.29A.00.34A.02.06A.02.18A.02.36A.02.37A.02.45A.02.46A.02.48A.02.49A.02.54A.02.55A.02.76E.00.04E.00.05E.00.16E.00.17E.00.20E.00.21E.01.04E.01.12E.01.17E.02.13E.02.17E.02.35E.02.39E.02.47E.04 | .54E.04.01E.04.02E.04.03E.04.08E.04.10E.04.12E.04.13E.04.17E.04.18E.04.23E.04.29E.04.54E.04.254H.00.42H.00.81H.01.00H.01.05H.01.08H.01.14H.01.18H.01.21H.02.00H.02.02H.02.03H.02.04H.02.05H.02.07H.02.09H.02.10H.02.70H.03.00H.03.02H.03.05H.03.54

Related guides you might find useful

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →

New boiler cost 2026

Realistic UK prices for a swap.

Read →