Smell gas? Leave the property and call the National Gas Emergency line on 0800 111 999

Worcester Bosch fault code

Worcester Bosch 1021: hot water temperature sensor defective

Engineer only

Worcester Bosch describes 1021 on Greenstar 8000 Life boilers as: hot water temperature sensor defective.

What you can safely do

There is nothing you can safely do yourself with this one. Leave the boiler off and book an engineer.

Find a Gas Safe engineer near you Opens the official Gas Safe Register search.

Applies to: Greenstar 8000 Life. Codes can differ between models, so check your manual.

From Worcester Bosch's own fault tables. Your model name is usually on the front of the boiler or in the user manual.

Model	Meaning
Greenstar 8000 Life	Hot water temperature sensor defective

Can I fix Worcester Bosch 1021 myself?

No. It needs a Gas Safe registered engineer to diagnose. Tell them the exact code and your boiler's model name.