As a BMW car owner, there may come a time when you encounter problems with your vehicle’s heater.
In this article, we’ll take a closer look at some common issues that may cause your BMW heater to stop working and provide some tips on how to troubleshoot and fix them.
Why is the heat in BMW not working?
There are several reasons why the heater in your BMW might suddenly stop working. Some of these causes are more common than others, but it’s important to know what could potentially be causing the issue so you can take the necessary steps to resolve it.
- Low coolant levels
- Malfunctioning thermostat
- Damaged heater core
- Faulty blower motor
Low coolant levels
One of the most common reasons why your BMW heater might not be working is due to low coolant levels. Coolant is responsible for keeping your engine at a safe operating temperature, but it also plays a crucial role in providing heat for the interior of your car.
Coolant, also known as antifreeze, is a liquid that helps regulate the temperature of your engine.
It is usually a mixture of water and ethylene glycol or propylene glycol and can be found in a reservoir tank under the hood of your BMW. This tank is typically labelled with a bright cap marked “coolant” or “antifreeze.”
Low coolant levels can occur due to leaks in the system or simply from evaporation over time.
Reasons: Low coolant levels in your BMW can be caused by a variety of reasons.
One potential cause is a leak in the coolant system, which could be due to a damaged hose or radiator. Over time, these components can wear out and develop small holes, causing the coolant to slowly leak out.
Another reason for low coolant levels is evaporation. Coolant can slowly evaporate over time, especially if it’s been a while since you last had your system topped up.
Symptom/sign: If your BMW’s coolant levels are low, you may notice a decrease in heat coming from the vents. This is because there isn’t enough coolant circulating to properly warm up the air before it reaches the vents.
You may also notice that the temperature gauge on your dashboard is reading higher than normal, indicating that your engine is running hotter due to low coolant levels.
Additionally, if you check under the hood and see a visible drop in coolant levels in the reservoir tank, this could be a sign of a leak or evaporation.
Some examples of how low coolant levels can affect your BMW heater include:
- Your car blowing cold air instead of warm air from the vents
- The temperature gauge on your dashboard displays a high temperature reading
- The engine running hotter than usual, potentially causing damage if not addressed
- A decrease in overall heating effectiveness within the vehicle’s cabin.
Self-inspect: Before taking your BMW to a technician for low coolant levels on your heater, there are some self-inspection steps you can take.
First, start by checking the level of coolant in the reservoir tank under the hood. If it is below the recommended level, you may leak or need to add more coolant.
Next, inspect the hoses and connections for any visible leaks or damage.
Additionally, make sure that all vents and openings in the heating system are clear of debris or obstructions.
It’s also essential to check your vehicle’s owner’s manual for specific instructions on how to properly check and refill coolant levels for your particular BMW model.
Error code: If your BMW is equipped with an onboard computer system, you may receive an error code related to low coolant levels. This can appear as a warning light on your dashboard or a message displayed on the screen.
The error code related to Low coolant levels on the BMW Heater Not Working is as below:
- P0128 – Coolant Thermostat (Coolant Temperature Below Regulating Temperature)
- P2181 – Engine Cooling System Performance
- P1290 – Low Coolant Light On
- P2185 – Engine Coolant Temperature Sensor 2 Circuit High Input
Basic troubleshooting: If you’re experiencing issues with your BMW heater, there are some basic troubleshooting steps that you can try before bringing your vehicle to a technician.
These include checking the coolant levels and refilling if necessary, inspecting hoses and connections for leaks or damage, clearing any debris or obstructions from vents and openings in the heating system, and monitoring for error codes related to low coolant levels.
Solutions: If you’ve determined that the issue with your BMW heater is due to low coolant levels, there are a few solutions that can help resolve the problem.
First, ensure that the coolant reservoir is filled to the proper level and check for any leaks in the system. If necessary, replace any damaged hoses or connections.
Additionally, consider flushing out the old coolant and replacing it with fresh fluid.
It’s also recommended to have your cooling system inspected and serviced regularly by a certified technician to prevent future issues with low coolant levels and maintain the optimal performance of your BMW heater.
So, taking these measures can help resolve low coolant level-related problems in your BMW Heater Not Working effectively.
Costs: The cost of resolving low coolant level-related issues with your BMW heater will vary depending on the extent of damage and the specific solutions needed.
Sometimes, it may be as simple as refilling the coolant reservoir or replacing a damaged hose, which can be relatively inexpensive.
However, if there is significant damage to the system or other underlying issues, it could result in more expensive repairs or replacements.
It’s best to consult with a certified technician for an accurate estimate of costs related to low coolant levels on your BMW Heater Not Working.
Malfunctioning thermostat
Another common issue that can cause a BMW heater not to work is a malfunctioning thermostat.
The thermostat regulates the flow of coolant through the system and if it’s not functioning properly, it can lead to insufficient heat being produced by the heater.
A thermostat is a small component attached to the engine of your BMW that helps regulate the temperature by opening and closing to allow coolant to flow through the system.
It can typically be found near the top of the engine, connected to the upper radiator hose. In some models, it may also be located near the bottom of the engine block.
Reasons: The reasons for a malfunctioning thermostat on your BMW heater can vary.
It could be due to wear and tear, electrical issues, or even debris buildup within the system.
Symptom/sign: One of the most common symptoms of a malfunctioning thermostat on your BMW heater is when you notice that the temperature gauge is not working properly.
This could mean that the engine is either running too hot or too cold, resulting in inadequate heat being produced by the heater.
You may also experience fluctuations in temperature while driving or even a complete lack of heat coming from the vents.
Self-inspect: Before bringing your BMW to a technician for a potentially malfunctioning thermostat, there are a few self-inspection steps you can take.
Start by checking the coolant levels and ensuring that they are at the correct level.
You should also inspect the thermostat housing for any cracks or leaks, as well as check the electrical connections to make sure they are secure.
If you have access to an OBD-II scanner, you can also use it to read any error codes related to the thermostat.
By performing these self-inspections, you may be able to identify and address minor issues before they become major problems with your BMW Heater Not Working.
Error code: Some common error codes related to a faulty thermostat include
- P0128 (coolant temperature below thermostat regulating temperature)
- P2181 (cooling system performance)
- P0597 (thermostat heater control circuit)
Basic troubleshooting: Before heading to a mechanic, there are a few basic troubleshooting steps you can take if your BMW heater is not working due to a malfunctioning thermostat.
You can try replacing the thermostat itself, checking and cleaning any clogs in the cooling system, or flushing out the entire system with fresh coolant.
Solutions: If the basic troubleshooting steps do not solve the issue, then it’s time to consult a professional mechanic.
They will be able to diagnose and pinpoint the exact problem with your BMW’s heater and thermostat. Depending on the specific issue, they may recommend replacing the entire thermostat or just certain components within it.
In some cases, a simple recalibration of the thermostat may also be necessary.
Costs: The cost of fixing a malfunctioning thermostat on your BMW’s heater can vary depending on the severity of the issue and the specific parts that need to be replaced.
On average, you can expect to pay anywhere from $100 to $500 for a thermostat replacement in a BMW. However, this cost may increase if additional parts or repairs are needed.
It’s always best to get a quote from your mechanic before proceeding with any repairs.
Damaged heater core
In some cases, a malfunctioning heater may be caused by a damaged or clogged heater core.
The heater core is responsible for heating the air that is blown into your car’s cabin, so if it becomes damaged or clogged with debris, it can affect the performance of your BMW’s heater.
Reasons: There are several reasons why a heater core may become damaged or clogged.
One common reason is due to neglecting regular maintenance and failing to replace the coolant as recommended by the manufacturer. Over time, this can cause buildup and blockage in the heater core.
Another potential cause could be a leaking water pump, which can introduce contaminants into the coolant system and lead to damage of the heater core.
In some cases, debris from outside sources such as leaves or dirt can also find their way into the coolant system and cause issues with the heater core.
Symptom/sign: If your BMW’s heater core is damaged or clogged, you may experience a lack of heat coming from the vents when the heater is turned on.
This can also lead to uneven heating in different areas of the car or no heat at all.
Additionally, you may notice a sweet smell inside your car, which can be a sign of coolant leaking from the damaged heater core.
Self-inspect: Before taking your BMW to a mechanic, there are some steps you can take to self-inspect the heater core.
Start by checking for any leaks or dampness around the dashboard area, as this could indicate a damaged heater core.
Next, check the coolant level and make sure it is at the recommended level. You can also try flushing out the coolant system to remove any potential blockages in the heater core.
Error code: If you’re experiencing issues with your BMW’s heater not working, it’s important to pay attention to any error codes that may appear on your vehicle’s dashboard.
Some common error codes associated with a damaged heater core include P0128, which indicates a low coolant temperature, and P2181, which points to an issue with the engine cooling system.
Basic troubleshooting: If you notice any of these error codes, there are a few basic troubleshooting steps you can take before seeking professional help.
First, check the coolant level and top it off if it’s low.
Next, try flushing out the coolant system to see if that resolves the issue.
If not, then it’s best to bring your car to a qualified technician who can properly diagnose and repair any issues with your BMW’s heater core.
Solutions: While a damaged heater core can be a frustrating issue to deal with, there are solutions available.
In some cases, the heater core may need to be replaced entirely, but this will depend on the extent of the damage.
In other situations, a simple repair or cleaning may solve the problem.
Costs: The cost of repairing or replacing a damaged heater core can vary depending on the severity of the issue and the specific model of your BMW.
In general, repairs can range from a few hundred dollars to over a thousand dollars.
Faulty blower motor
If your BMW’s heater is blowing cold air, the issue could be with the blower motor.
The blower motor is responsible for taking in outside air and blowing it through the heater core, which then heats up the air before it is released into the cabin. Its also helps to circulate cold air from the air conditioning system.
The blower motor in a BMW is located under the dashboard on the passenger side of the vehicle.
Reasons: There are several potential reasons for a faulty blower motor in your BMW.
It could be due to a blown fuse, a damaged resistor, or a worn out motor itself.
Additionally, debris and dirt can build up in the blower motor over time, causing it to work less efficiently or even stop working altogether.
Symptom/sign: If your blower motor is not functioning properly, you may experience a lack of airflow or inconsistent air temperature from the vents.
You may also hear unusual noises from under the dashboard when you turn on the heater or air conditioning.
Self-inspect: Before taking your BMW to a technician for blower motor issues, there are a few things you can check on your own.
First, make sure the fuse for the blower motor is intact and not blown. You can also inspect the wiring and connections to see if there are any visible damages or loose connections.
Additionally, try changing the fan speed settings to see if that makes a difference in airflow.
Error code: If your BMW has a diagnostic system, it may display an error code related to the blower motor issue. This can help pinpoint the specific problem and make repairs easier for technicians.
Some common error codes related to faulty blower motors include “Blower Motor Circuit High” or “Blower Motor Speed Control Malfunction.”
It’s important to take note of any error codes and share them with your technician for a more accurate diagnosis.
Basic troubleshooting: In some cases, basic troubleshooting can solve the issue without having to visit a technician.
This includes checking and replacing the cabin air filter, which can become clogged and restrict airflow from the blower motor.
Solutions: If the above troubleshooting steps do not solve the issue, it may be time to consider replacing the blower motor altogether.
This can be done by a professional technician, or if you have experience with car repairs, it can be a DIY project.
You can also opt for a remanufactured blower motor which is more cost-effective than buying a brand new one.
Regular maintenance and cleaning of the blower motor can also help prevent future issues.
Costs: The cost of repairing or replacing a faulty blower motor will vary depending on the specific issue and the labor rates of your chosen technician.
However, on average, you can expect to pay between $200-$500 for parts and labor.
Source
https://slautoworks.com/bmw/5-reasons-bmw-heater-blowing-cold/
https://www.competitionbmw.com/why-is-your-bmw-car-heater-blowing-cold-air/