The answer to 'how to fix carbon monoxide detector' is to first check the detector's batteries and replace them if needed. If the detector is still not working properly, you may need to clean the sensor or replace the entire unit.
Carbon monoxide detectors typically last 5-7 years, so if your detector is older, it's a good idea to replace it entirely. Always follow the manufacturer's instructions for installation, maintenance, and testing your carbon monoxide detector to ensure it is working correctly and providing the protection your home needs.