What might indicate a problem with the heater in a vehicle?

A low coolant level is a strong indicator of a potential issue with the vehicle's heating system. The heater core, which is responsible for providing warm air to the cabin, relies on engine coolant to function properly. If the coolant level is low, there may not be enough fluid circulating through the heater core, leading to insufficient heat in the vehicle’s interior. This could also suggest possible leaks in the cooling system or overheating issues, which can further impact the vehicle's overall performance.

While warm air from the AC can be a sign pertaining to the air conditioning system, it does not relate directly to the heater itself. Clunking noises and vibrations in the steering wheel are typically associated with problems in the suspension, steering, or drivetrain, rather than the heating system. Understanding the relationship between coolant levels and cabin heating is crucial for diagnosing and resolving heater issues effectively.