Technicians often overlook two key parts of the HVAC system during routine maintenance, the heater and cabin blowers. This is often due to accessibility, yet these components are not only crucial to optimal HVAC performance, but also to passenger comfort and safety and should not be over looked. 

 
Integral to the EC system, the heater controls cabin comfort by supplying warm air to passengers. In most vehicles, it’s located behind the dashboard or in the HVAC module.  Hot coolant from the engine block passes through the heater, warming the intake air blown on its surface by the interior blower, before continuing into the cabin. In addition to warming the cabin, it also helps remove condensation on the vehicle’s windows, greatly improving visibility and safety while driving.

A common issue is residue in the heater core and the heater tubes from a variety of sources which can accumulate and eventually block coolant flow and reduce the heater’s operational efficiency. This can stem from using the incorrect or poor quality coolants.  Also worn-out or broken thermostat valves may restrict coolant flow and prevent the heater from operating correctly, while corrosion from damp conditions can lead the heater core to leak. Leaks can cause coolant levels to drop, leading to poor heater performance and more extensive damage to other engine components. 

Depending on the car model, the typical replacement time of the heater varies between two and three hours. In some advanced vehicles, it can take more. 

Interior blowers ensure air flows through the intake and enters the heat exchangers, such as the heater and the evaporator. As air passes through the heat exchangers, the blower can distribute warm or cool air throughout the cabin. Blowers are typically situated in the HVAC module between the cabin and engine compartment. The interior blower is potentially vulnerable due to its plastic elements that can be fragile. Additionally, as an electrical device, it is sensitive to failures within the vehicle's electrical system. 

Blower issues can be caused by a clogged or defective cabin air filter, while the most common reasons for interior blower problems stem from failures in the vehicle's electrical system, restricted flow in the air intake system and improper handling during its installation. 

Blowers in vehicles used for commercial activities, such as taxis, trucks and buses endure more significant wear simply because of the mileage they cover and the working hours they operate. 

Depending on the car model, the typical replacement time for a blower can last anywhere between two and three hours. 

Nissens point out that a premium replacement heater can avoid fitting issues. The same rule applies to blowers, where smooth operation, efficiency and durability are essential for cabin comfort. Poor quality blowers can generate noise and interfere with a car's electronics or radio. Furthermore, a malfunctioning or inefficient blower can quickly cause expensive AC system failures, including compressor overload and breakdown. No airflow through the evaporator means poor refrigerant state change, leading to poor system performance and exposing the AC compressor to fluid intake or overload. Because replacement of both heaters and blowers it also makes sense to use a quality component with a long life. 

All Nissens products are designed and manufactured to Genuine Nissens Quality standards, which means they are engineered to deliver high performance and durability and to fit perfectly where the original part once was. Whenever required, additional components, such as nuts, bolts, clips, cassette foam, ducts, etc., are supplied inside the product box.

The Nissens range provides great market coverage for all vehicle segments and even includes 120 blower and heater models for new energy vehicles, making it the ideal solution for workshops. Nissens' heater program encompasses +350 items, caters to 1,000 OE part numbers, and covers 80% of the car parc. Over 320 Nissens blower models match 1,100 OE part numbers and provide 70% coverage. 

Nissens' heaters and blowers are available from stockist nationwide.