Heating the car no longer works: causes and solutions

Last updated of 4 April 2025 by Maxime de Prinel

AND Heating in the absence In the car it can be particularly frustrating, especially in winter. If the heating system no longer works or blows cold air, different causes are possible.

This ultra-common guide explains you Because the heating of your car no longer warns itself, how to repair it and what solutions to adopt To find optimal comfort in your cabin.

Why does the heating of the car doesn’t warm up anymore?

Heating a car is based on refrigerant circulating in the heating radiator. Several Flies or dysfunctions It can prevent heating from working properly.

The most common causes of a rupture heating

1️⃣ Fluid cooling level too low : If there is a lack of liquid in the circuit, the hot water no longer reaches the heating radiator.
2️⃣ Heating radiator blocked : The accumulation of limestone, rust or impurities can block the circulation of the liquid.
3️⃣ Defective thermostat : An open -position thermostat prevents the engine from reaching the necessary temperature.
4️⃣ Heating control problem : An electrical fault or an air shocker blocked can prevent the distribution of heat.
5️⃣ Defective water pump : The cooling liquid is no longer circulating, which prevents heating from working.
6️⃣ Fans problem : If the hot air does not blow, it can be a breaking of the fan or grilled resistance.

🚨 To know : If the car overheats the heating at the same time, it no longer works, stop the vehicle immediately and check the level of the refrigerant.

1. Check and fill the refrigerant

✔ Hood And identify the expansion vase.
✔ Check the liquid level (It must be between the reference points and max).
✔ Add liquid If necessary, with the good type recommended by the manufacturer.

🚨 Attention : Never open the cooling liquid cap hot engineunder the penalty of serious burns.

2. Pure the cooling circuit

If air bubbles block the circulation of the liquidyou have to perform a Purge du around.

✔ Heal the engine With the open expansion vase limit.
✔ Activate heating to the maximum Force the circulation of the liquid.
✔ Check the increase in temperature and close once it is purged.

3. Check the engine thermostat

An blocked thermostat can prevent the engine from sending hot water to the heating radiator.

✔ Start the car and heat.
✔ Touching the radiator tubes : If they remain cold while the engine is hot, the thermostat is definitely low.
✔ Replace the thermostat if necessary (cost between 30 Et 100 €depending on the model).

4. Take the heating radiator

A dirty radiator blocks the circulation of the liquid.

✔ Disassemble the radiator tubes heating.
✔ Rinse with a pressure water tube To eliminate deposits.
✔ Reconnect and purge the circuit after cleaning.

5. Check and replace the resistance to the fan

Yes the The fan does not blow warmer or cold airResistance can be toasted.

✔ Try the fan by changing the speeds.
✔ If no speed works, replace resistance (It cares about the piece approximately 20-50 €).

Why doesn’t my heating work in my car?

🚗 Different possible reasons:

• Cooling liquid too low or clogged circuit ❌
• Dirty heating radiator ❌
• Defective thermostat ❌
• Heating control or blocked air valve ❌
• Electrical problem or grilled fuse problem ❌

📌 Solution: Start by checking the level of liquidThen test the other components step by step.

Why is my heating fan no longer works?

If the fan does not blow Neither hot nor cold airIt is possible that:
✔ The blower of the blower is grilled 🔥
✔ Fan resistance is HS 🔧
✔ The fan engine is damaged ⚡

📌 Solution: Test the fuse and priority resistance before dismantling the fan.

The heating of my car blows cold: what to do?

If your heating spread only cold airDifferent causes are possible:
✔ lack of refrigerant 🛑
✔ The thermostat has constantly opened ⚠
✔ Blocked heating radiator 🔄
✔ Problem with the heating control valve 🔧

📌 Solution: Start by checking the refrigerantThen test the other elements if the problem persists.

When to consult a mechanic?

If after these checks:
❌ The heating does not work yet 🔥
❌ A unusual smell of cooling liquid 🚨 appears
❌ Your engine heated abnormally 🌡 🌡

➢ It is recommended to consult a mechanic. Some repairs such as Replacement of the heating radiator OR water pump Request a specific know-how.

📌 Average cost of repairs:
✔ Purge circuit: From 50 to 80 €
✔ Replacement of the thermostat: 30 to 100 €
✔ Unogging of the heating radiator: 80 to 200 €
✔ Change of heating fan: From 100 to 300 €

🔹 Step 1: check the refrigerant level
🔹 Step 2: Eliminate the circuit if necessary
🔹 Step 3: test the engine thermostat
🔹 Step 4: Clean or replace the heating radiator
🔹 Step 5: check the resistance to the fan and the fan

A heating for rupture car can be caused by a simple lack of liquid or a more serious problem. Deleting you can identify the cause And Effectively repair the heating system.

📌 Last advice: Do not delay actingbecause a heating problem can Hide a concern about cooling the engine more serious.