265 error code
Heat demand lower than energy supplied
What does Worcester Bosch Legacy Greenstar CDi, Si and i gas boilers 265 mean?
Worcester Bosch documents 265 for the Legacy Greenstar CDi, Si and i gas boilers as “Heat demand lower than energy supplied”. This is the quick answer for this exact boiler range. The display identifies the condition detected by the appliance, but it does not by itself prove which component has failed. Confirm the complete code, boiler model and operating situation before using any reset or repair instructions. Similar codes on another Worcester Bosch range can have a different meaning.
The code identifies the condition detected by the product; it does not always identify the failed component on its own. Confirm the full code and exact model before ordering parts or attempting a reset.
The Worcester Bosch Legacy Greenstar CDi, Si and i gas boilers 265 error code indicates worcester Bosch documents 265 for the Legacy Greenstar CDi, Si and i gas boilers as “Heat demand lower than energy supplied”. This is the quick answer for this exact boiler range. The display identifies the condition detected by the appliance, but it does not by itself prove which component has failed. Confirm the complete code, boiler model and operating situation before using any reset or repair instructions. Similar codes on another Worcester Bosch range can have a different meaning. This guide explains what the code means, the symptoms and likely causes, the checks that are safe to make, and when to stop and arrange an authorised repair.
Symptoms you may notice
- The Legacy Greenstar CDi, Si and i gas boilers display shows 265.
- Heating or hot-water operation may pause, lock out or continue with reduced functionality, depending on the code type.
- A warning light, loss of heat, unusual cycling or a pressure change may also be present.
- Record when the code appears and whether it returns after the boiler cools.
Common causes
- The appliance has detected the documented condition: Heat demand lower than energy supplied.
- Wiring, a sensor, circulation, combustion, pressure or an external control may be involved, depending on the exact model.
- Installation conditions or an interrupted supply can sometimes trigger a related indication.
- A qualified diagnosis must test the circuit described in the manufacturer instructions; the code alone is not a parts diagnosis.
Before you start troubleshooting
Use the display, rating label or product menu to confirm the exact model. Similar-looking codes can have different meanings across product generations and regions.
- Record the complete code before switching the equipment off.
- Check only user-accessible controls, filters and external connections described in the manual.
- Do not open gas, refrigerant, combustion or electrical compartments.
Troubleshooting steps
- 1. Record the complete code and exact model from the data plate.
- 2. Check the pressure gauge, power and user controls only where the operating manual permits.
- 3. Check for a frozen external condensate pipe or an obvious external leak without removing the casing.
- 4. Compare the display with the linked manufacturer guidance for this product.
- 5. If the code returns, stop repeated resets and arrange an authorised Gas Safe engineer.
Can you fix this error code yourself?
The safest next step depends on the exact model and the cause behind the code. External checks may help, but a returning fault needs professional diagnosis.
A successful reset is not proof that the underlying issue is fixed. If 265 reappears, note when it happens and give that information to the service engineer.
Reset instructions
Use only the reset control and sequence stated in the operating instructions for the exact boiler. Attempt one reset only when the manual permits it and there is no smell of gas, water leak or sign of overheating. A reset can clear a lockout display without correcting its cause; if the code returns, record it and obtain professional help.
Applicable products and models
Legacy Greenstar CDi, Si and i gas boilersGreenstar CDi / Si / iLegacy rangesWhen to contact a professional
Contact a Gas Safe registered engineer or Worcester Bosch service support if 265 returns after the permitted user check, the boiler will not operate, pressure repeatedly falls, or diagnosis requires internal access. Give the engineer the complete code, model, serial number and the circumstances in which it appeared.
Frequently asked questions
What does Worcester Bosch Legacy Greenstar CDi, Si and i gas boilers 265 mean?
Worcester Bosch documents 265 for the Legacy Greenstar CDi, Si and i gas boilers as “Heat demand lower than energy supplied”. This is the quick answer for this exact boiler range. The display identifies the condition detected by the appliance, but it does not by itself prove which component has failed. Confirm the complete code, boiler model and operating situation before using any reset or repair instructions. Similar codes on another Worcester Bosch range can have a different meaning.
Can I fix Worcester Bosch Legacy Greenstar CDi, Si and i gas boilers 265 myself?
Some external checks may be suitable for the user, but the result depends on the exact model and cause. Use the official manual and arrange service if the code returns.
Should I reset the product after code 265?
Use only the reset control and sequence stated in the operating instructions for the exact boiler. Attempt one reset only when the manual permits it and there is no smell of gas, water leak or sign of overheating. A reset can clear a lockout display without correcting its cause; if the code returns, record it and obtain professional help.
When should I arrange a repair?
Contact a Gas Safe registered engineer or Worcester Bosch service support if 265 returns after the permitted user check, the boiler will not operate, pressure repeatedly falls, or diagnosis requires internal access. Give the engineer the complete code, model, serial number and the circumstances in which it appeared.