24 error code
ACV Kompakt HR eco 24 error code – S2 return-sensor fault
What does ACV Kompakt HR eco combi condensing boiler 24 mean?
ACV documents display code 24 for the Kompakt HR eco 24/28 and 30/36 combi boilers as: S2 return-sensor fault.
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 ACV Kompakt HR eco combi condensing boiler 24 error code indicates aCV documents display code 24 for the Kompakt HR eco 24/28 and 30/36 combi boilers as: S2 return-sensor fault. 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 fault indicator flashes and the temperature display shows 24. The boiler may lock out, stop firing, or interrupt central-heating or domestic-hot-water operation.
Common causes
The official table assigns this value to the S2 return-sensor fault group. Its wiring may be open or S2 may require replacement.
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
Record code 24 and the exact Kompakt HR eco model. Check only the visible pressure, electrical supply, thermostat demand and external controls permitted by the operating instructions. Internal sensor, fan, ignition, gas-valve, relay and combustion tests require a qualified 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 24 reappears, note when it happens and give that information to the service engineer.
Reset instructions
After the underlying fault has been corrected, hold the reset button for five seconds as specified in section 8.1 of the official manual. If code 24 returns, stop resetting and arrange professional diagnosis.
Applicable products and models
Kompakt HR eco combi condensing boilerKompakt HR eco 24/28; Kompakt HR eco 30/36Official installation manual, © 2022 ACV InternationalWhen to contact a professional
Contact ACV support or a qualified heating engineer when code 24 persists, returns after a permitted reset, or requires internal testing, adjustment or component replacement.
Frequently asked questions
What does ACV Kompakt HR eco combi condensing boiler 24 mean?
ACV documents display code 24 for the Kompakt HR eco 24/28 and 30/36 combi boilers as: S2 return-sensor fault.
Can I fix ACV Kompakt HR eco combi condensing boiler 24 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 24?
After the underlying fault has been corrected, hold the reset button for five seconds as specified in section 8.1 of the official manual. If code 24 returns, stop resetting and arrange professional diagnosis.
When should I arrange a repair?
Contact ACV support or a qualified heating engineer when code 24 persists, returns after a permitted reset, or requires internal testing, adjustment or component replacement.