What to check, in order
- Don't try to fix it yourself
Worcester's manual says not to try to put E2 right yourself.
- Call a Gas Safe registered engineer
Tell them the code on the display.
When to call a Gas Safe engineer
Worcester's service booklet points to a corroded connector or a faulty sensor or sensor lead. The engineer replaces the sensor or its lead.
A repair visit will usually check the sensor's reading and its wiring.
- Note the model and serial number. They're on a label on the data badge, usually under the boiler or behind the front cover.
- Write down the exact code, and what the appliance was doing when it appeared.
- Check whether it's still under warranty. If it is, the repair may cost you nothing.
Quick answers
What does the Worcester Bosch E2 fault code mean?
The temperature sensor (NTC) on the heating flow is faulty, so the boiler can't read the water temperature.
Can I fix Worcester Bosch E2 myself?
Engineer only (engineer visit). Start with: don't try to fix it yourself; call a Gas Safe registered engineer. Worcester's service booklet points to a corroded connector or a faulty sensor or sensor lead. The engineer replaces the sensor or its lead.
Is Worcester Bosch E2 worth repairing?
Worth fixing. A flow sensor is a small part, though it has to be fitted by an engineer.
Checked against
- Worcester Bosch Greenstar CDi Classic user instructions (PDF)
- Worcester Bosch Greenstar CDi Classic engineer's service booklet (PDF)
Last reviewed October 2026. Manufacturers update their pages, and your manual is the final word. Spotted a mistake? Email contact@appliance-error-codes.com.