What could be the reason for the heater in my Hyundai i20 not functioning properly?

It is not unusual for the Hyundai I20's heater to stop working, which is often due to common issues not specific to Hyundai vehicles. One main reason for this is insufficient coolant levels, as the HVAC system cannot function properly without it. Low coolant levels can lead to thermostat and radiator problems, resulting in a loss of climate control and cabin heat. A malfunctioning thermostat can also cause coolant leaks and radiator issues. Be sure to inspect for coolant leaks and a cracked thermostat housing. If the blower motor or resistor is faulty, it can completely disable the heat as they are responsible for pushing warm air through the vents. Another known issue is the heater core becoming clogged over time, causing coolant blockages and possible leaks. Replacing the heater core can cost between $540 and $900 for parts and labor.