Worcester Bosch · Greenstar 2000 Combi
1021 boiler fault code
Greenstar 2000 Combi
Get a Gas Safe engineer
Free. Enter your postcode.
Renting? Report it to your landlord or housing provider first. They are responsible for gas safety and boiler repairs, and the repair should not cost you.
What 1021 means
Hot water temperature sensor faulty
Safe check
Note the code. Do not open, adjust, or repeatedly reset the boiler. Contact a Gas Safe registered engineer.
When to contact an engineer
Contact a Gas Safe registered engineer to investigate this fault.
Safety notice
A boiler fault code alone is not a gas or carbon-monoxide emergency. If you smell gas, a CO alarm sounds, anyone feels unwell, or there is an unsafe flame, leave and call 0800 111 999 from outside.
Source and provenance
- Worcester Bosch Greenstar 2000 Installation, Commissioning and Servicing Instructions (2023/06) · document 6721839340 · §11.2 “Fault code table”, code 1021, printed p. 83
installation, commissioning and servicing instructions
2023/06 · document 6721839340