Car Heater Not Working: 7 Common Reasons To Follow Up
Winter is a season with extreme weather patterns beyond human endurance if we appear without specialized protective shields, especially for children and the elderly. Not only will it feel cold when walking in the middle of an intersection, but even in a car, you will also get the chill with air icing up blocking the window view. And that’s why you need a heater that runs well before winter hits. A car heater not working will be a threat to your health as well as that of your beloved car in the long run.
With that said, Car From Japan will point out some of the causes of car heater problems and a few tips to avoid encountering these undesirable troubles on your winter trip towards the North in the future.
How Does Car Heating System Work?
The way car heater works is easy to understand, even for those not specialized in technical machinery. In particular, the car heater will take heat from the engine. So it takes time for the engine to warm up for a few minutes before you can notice the effect of the heating mode on the car.
To turn on the heating mode in the car, the driver first needs to press the car defrosting button to dissolve the fog on the windshield and windows on cold or foggy days. The driver then starts the engine, which accelerates the temperature rise in the cabin. At this moment, car heaters do not generate heat immediately. If the outdoor temperature is too low, the car has been used for a long time, the engine is large, or the vehicle runs on diesel fuel, the heating mode will take longer to take effect. The driver can set the desired temperature and start the car heater by turning on the fan and adjusting it to the preferred speed.
Many people still mistakenly think that the car heater and air conditioner are the same. Another misconception about car heaters is that car AC is a two-way conditioner, which has both the effects of cooling and heating. Therefore, many people often press the A/C button to start it. However, car air conditioners only have one way of blowing cool air. And the car heater warms the cabin thanks to the heat released during the engine operation.
Why Car Heater Not Working: 7 Potential Issues To Take Note From
The reasons car heater not getting hot are unpredictable because you can never anticipate anything happening within one complex system. Here are the 6 most common causes of the unheated car condition for timely detection of related problems.
1. Insufficient Or Leaking Coolant
The coolant plays a vital role in the car’s air conditioning systems and engine operation, including the heating processes. During our drive, a large amount of heat will be generated due to the fuel combustion in the cylinder. That’s why the coolant is there, acting as a temperature equalizer of the engine and vehicle in general.
Part of the heat exhausted from the engine will radiate outside and contact with other parts, which in the long run can lead to breakdowns and affect the car’s ability to function properly. In many cases, lubricants at a temperature of 200 – 300 degrees will spontaneously ignite, leading to an increased possibility of fire and explosion. At these times, the car coolant becomes a bridge to transfer heat from the engine to the cooler. Thereby limiting the situation where the engine temperature exceeds the permissible limit.
If you encounter the heater in car not working situation, the insufficient coolant may be one of the most common causes. The low coolant level will prevent the vehicle’s heating system from working effectively. As the level recedes, air will appear in the tank, causing localized hot and cold spots that restrain performance. If there isn’t enough liquid to reach the heating fault, it won’t be able to blow warm air into the car through the vent. What’s more dangerous is that the coolant may leak out, causing a short circuit and humidifying surrounding parts.
Therefore, it is crucial to check the coolant tank regularly to keep the heater working well. The way to do is very simple because you only need to see the coolant indicator light. If the warning light appears, the engine temperature is too hot.
Experts recommend drivers should add car coolant after the first 60,000 kilometers and 40,000 kilometers more for the next time fill. Also, remember to take your vehicle to a repair shop periodically to have it checked for liquid leakages.
2. Damaged Heater Core
The second common cause leading to the car heater not working is the heater core. The heater core has a radiator-like structure, made from aluminum alloy with tubes that transport coolant in and out and distribute heat to warm the whole car.
If the heater core problems arise, the coolant cannot spread widely, and the fan will be blocked. Moreover, the core can easily suffer from rusting. Debris and particles that make their way into the coolant system might block your heater core. In general, this issue happens less often than the others but still exists to get on your nerves.
The signs of a broken heater core can be easy to recognize if you pay close attention during daily trips. You can smell a rather strange strong sweet-like smell in the cabin, and it will grow stronger by the day. It is the smell of leaking radiator fluid. You may also encounter some other problems such as car windows blurring for no reason, the engine frequently overheating, cool air escaping from the vents, or you constantly having to refill the coolant tank. In case your heater core meets those signs, the best way is to bring it to the auto shop to prevent issues from arising.
3. Thermostat Issue
The thermostat is another vital part contributing to the car heater’s efficient operation. It helps regulate the car’s temperature, avoids emitting too much heat, and ensures the cooling and heating system works smoothly.
With only a little attention, you will be able to precisely identify the problem without trying to find out and catch headaches because of confusion. In most cases, when the thermostat gets stuck closed, it’s because the coolant has been contaminated with a mix of other types. This causes debris to build up around the thermostat, preventing it from opening. Another cause lies in the frequent coolant not being cleaned, which causes the thermostat valve to rust.
Moreover, if you see the temperature meter turn red within the first 15 minutes of driving, your thermostat may have failed. Not only that, if the engine is hot, but the radiator and upper radiator hose are cool, there must be a problem.
A faulty thermostat won’t be able to accumulate heat into the car, causing an unwanted car heater not working problem. When the thermostat closes, the engine temperature cannot be regulated, and other parts of the cooling system cannot do their job. If the thermostat gets stuck open, the engine will probably never reach the proper temperature and operate at full capacity.
Just by solving the core problem, your car heater will have a chance to return to a healthy condition faster, avoiding leaving you to suffer in the freezing cabin in the middle of winter.
4. Air Lock
To put it simply, airlocks are air bubbles entering the system’s inner spaces when you open it or when leakage happens, which appears to replace the fluid lines and prevent circulation.
The gurgling sound appearing in the front dash every time you start the engine could be a sign of air bubbles entering the heater core. This phenomenon will provoke many difficulties, and one of the most concerning problems is airlocks.
Causes of airlock can be a careless coolant-filling process, a bad radiator cap, or leak holes in the heater control valve. Airlocks in the heater core system will also cause oxidation, making it vulnerable to rust due to the corroded aluminum alloy layer after a long time of use.
With the above-mentioned consequences, you may now realize the importance of a heating process that says no to air pockets for the safety of the vehicle operation and your driving experience. To completely clear the airlock in the heater core, you need to seek help from experts or find out the most accurate and thorough way to fix the problem yourself.
There is one quite helpful way to handle the situation in advance. First, remove the coolant tank cap and fill the right amount of coolant after turning the heater to its highest setting. Start the engine while leaving the cap open, then let the car idle for a few minutes. If the coolant level drops while the thermostat is turned on, top it up. Air bubbles should be bled out as a result of this action. Replace the cap once the engine has warmed up and drive to test whether the heat output has returned.
5. Faulty HVAC Control System
HVAC stands for Heating Ventilating and Air Conditioning. The HVAC is a climate conditioning system in a car. As its name suggests, the smooth operation of the heater depends a lot on it. The function of the car heater is to generate and distribute heat to the entire area covered by the HVAC system. HVAC systems are used regularly and continuously, throughout the years and weather patterns.
That’s why regular system maintenance is essential. Full system maintenance brings several benefits, such as saving on repair or replacement costs and reducing driving shut-off. It can also save energy consumption while improving the efficiency of car components.
If you are still wondering why is my car heater not working every time, you can consider taking your beloved car to a professional repair shop to have parts checked and replaced before they face more serious problems.
6. Faulty Heater Blower Motor
Blower Motor is an electric motor that blows warm air through the vent. And it can run at different speeds to assist in managing the cabin temperatures.
When the blower motor faces problems, the heating and air conditioning system cannot work properly. It also causes the interruption of other components’ functions, such as the window defrosting function.
A broken or weak-functioning blower motor will cause many unwanted problems. Such as weak wind blowing through the vent, warm air that always blows at a fixed mode, or worse, no heat blowing out in the cold winter. The blower motor also catches the failing symptoms if it starts slowly, or makes squeak noises.
In general, self-checking the condition of the heater blower motor is a simple process. You only need a voltmeter, electrical tester, repair manuals, or mechanic guidance to make blower motor tests. Do not leave the heater problem in place for too long. Because it can cause a lot of trouble for you and your car. And beware, the bad things do not just arise in winter.
7. Broken Blower Motor Resistor
As the blower motor’s speed is continuously changed, the resistor will be under a lot of pressure, which can easily lead to undesirable damage. If there is a problem within, this part will cause the air conditioning system, especially the car heater, ineffective and create functioning obstacles.
Some common symptoms of a faulty blower motor resistor emerge from the blower motor. Because these are two parts that are closely related to each other during the operation of the heating system. You may encounter a problem when the blower stucks at one wind speed without being able to switch to another. Or you can not feel warm air coming out from the top front vent.
A malfunctioning motor resistor will upset the standard process of the ventilation system. So to always keep the air in the car clean and fresh, you must always keep the blower motor resistor under control.
Car Heater Not Working: Maintenance Tips
Drivers should regularly check the coolant level and add more if necessary. Detecting leaks to ensure stable operation of the heating system and car heater is also an important task.
The heater takes time to warm up the cabin, so the driver should not adjust or increase the temperature too much when starting the car. You can use the air recirculation feature to get the air inside to warm it up again. By doing this, the car can reach the desired temperature faster and avoid unpleasant odors.
>> See more: Car AC Smells Bad: The Causes And Solutions
For your reference, the cost of car heater repair is determined by its underlying issues. For other parts such as the blower or the thermostat, you can always easily replace them at a low cost. The coolant tank filling is also part of a low-cost maintenance process.
However, changing the heater core will be much more pricey. So, in order not to fall into a crisis of burning out your pocket for car repairs, keep some helpful car heater maintenance tips from experts. Your car will surely appreciate you very much.
Car Heater Not Working: Wrapping Up
As for now, you may have a better understanding of why your car heater not working properly for some reasons above. In general, car heaters, like most vehicle components working under the controls of a complex system, may cause more severe problems if not taken good care of regularly.
If your automobile requires frequent maintenance, consider replacing it by looking for our used cars for sale in Japan. You may be surprised by their quality.
For more helpful car maintenance tips, follow Car From Japan right today.