The answer to 'why is my air filter leaking water' is that a leaking air filter is often caused by a clogged or dirty filter, a problem with the HVAC system's condensate drain, or excess moisture in the air. The air filter may be leaking water if it has become saturated and can no longer effectively filter the air. This can happen if the filter is not changed regularly or if there is an issue with the HVAC system's condensate drain.
If the air filter is leaking, it's important to address the underlying issue to prevent further problems. This may involve changing the air filter, cleaning the HVAC system's condensate drain, or addressing any issues with excess moisture in the home. If the problem persists or you're unsure of the cause, it's best to call a professional HVAC technician to diagnose and fix the issue.