Quick answer
On Baxi boilers, fault code E20 means: Temperature sensor (thermistor) fault. The boiler has locked out for safety. Try the safe checks below and one reset; if the code returns, call a qualified gas engineer.
Smell gas? Don't use switches or flames, open windows, close the gas valve, leave the building and call your gas emergency number. Never open the boiler casing yourself.
Can I keep using the boiler?
Severity: Medium
The boiler has locked out for safety. Try the safe checks below and one reset; if the code returns, call a qualified gas engineer.
Common causes
- Faulty sensor or component
- Damaged wiring or a loose/corroded connector
How to fix it
- Press the boiler's reset button once and wait for it to restart
- Have a qualified gas engineer inspect the boiler; never open gas or flue parts yourself
Frequently asked questions
What does Baxi error E20 mean?
On Baxi boilers, fault code E20 means: Temperature sensor (thermistor) fault.
How do I fix Baxi error E20?
Start with these steps: Press the boiler's reset button once and wait for it to restart; Have a qualified gas engineer inspect the boiler; never open gas or flue parts yourself.
Is it safe to use the boiler with fault E20?
Severity: Medium. The boiler has locked out for safety. Try the safe checks below and one reset; if the code returns, call a qualified gas engineer.
Baxi boiler fault codes
E133Ignition failure, no flame detectedE118Water pressure too lowE117Water pressure too highE110Overheating (safety limit tripped)E125Water circulation faultE160Fan faultE28Flue (exhaust) faultE384False flame detectedE15Gas valve fault