Why is the oven not heating?
Tips for motorists

Why is the oven not heating?

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      Nothing is more appreciated in cold, dank weather than the opportunity to warm up. So you get into the car, start the engine, turn on the stove and wait for the heat to start flowing into the cabin. But time goes by, and your car is still a cold tin can. The stove is not working. Riding in such a car when it is cold outside is very uncomfortable, and even the windows fog up, or even become completely covered with frost. What is the reason? And how to solve the problem? Let's try to figure it out.

      How the car heating system is arranged and functions

      To make it easier to find and eliminate the cause of the malfunction, you need to understand how the car heating system works and what is the principle of its operation.

      В ее состав входят радиатор, вентилятор, воздуховоды, заслонки, соединительные трубки и устройство, регулирующее поток жидкости. Система отопления работает совместно с двигателя. Основным источником тепла в салоне автомобиля является мотор. А в качестве агента, переносящего тепловую энергию, служит . Разогретый мотор передает тепло антифризу, который циркулирует в замкнутой системе охлаждения благодаря водяной помпе. Когда печка выключена, охлаждающая жидкость отдает тепло радиатору системы охлаждения, который дополнительно обдувается вентилятором.

      The radiator of the heating system is located behind the front panel, two pipes are connected to it - inlet and outlet. When the driver turns on the heater, its valve opens, the stove radiator is included in the antifreeze circulation system and heats up. Thanks to the heating system fan, outside air is blown through the heating radiator and forced into the passenger compartment through the damper system. The radiator has many thin plates that effectively transfer heat to the blown air.

      By adjusting the flaps, you can direct the flow of warm air to the windshield, front door windows, driver's and passenger's feet, and in other directions.

      Air is blown into the heating system by a fan through a cabin filter, which prevents debris, dust and insects from getting inside. Over time, it clogs, so it should be changed periodically.

      If you open the recirculation damper, the fan will not blow cold outside air, but air from the passenger compartment. In this case, the interior will warm up faster.

      Since the heater actually additionally removes heat from the motor, the engine warm-up will slow down significantly if the stove is turned on immediately after it is started. It is better to wait until the coolant temperature reaches at least 50°C and then start heating.

      As an addition to a conventional heating system, an electric heater can be used, which works like a conventional boiler. In this case, water in the tank or air in a special chamber can be heated. There are also options for heated seat covers and other cigarette lighter powered heaters. But it's not about them now.

      Possible causes of lack of heat in the cabin and troubleshooting

      The interior will be warm if all components of the heating system are in good working order and function properly. Problems will begin if at least one of the elements goes haywire. Malfunctions of the engine cooling system will also in most cases lead to the termination of the heater. Now let's look at the specific reasons for the failure of the heating system.

      1. Low coolant level

      Insufficient coolant in the system will impair circulation and reduce heat transfer from the radiator. Cold or barely warm air will enter the cabin.

      Add antifreeze, but make sure there are no leaks first. The most critical places where tightness can be broken are the connecting pipes and their connections. A leak can also be found in the radiator itself - both the heater and the cooling system. A leaky radiator will need to be replaced. Patching holes with sealants will not give a reliable result, but with a high probability it will lead to clogging and the need to flush the entire system. The water pump may also be leaking.

      2. Airlock

      The circulation of antifreeze will be disrupted if an air lock has formed in the system. Air can get into the system during coolant replacement or due to depressurization. In this case, the stove also does not heat up, and cold air blows into the cabin.

      There are two ways to get rid of an airlock. The first is to place the car on a steep slope of about 30° or jack up the front of the car to the same angle, especially the side where the expansion tank of the cooling system is located. Then you need to start the engine and turn off the gas. This will allow all the air from the cooling and heating system to be transferred to the cooling radiator. Since its return hose is raised, the air will pass through it into the tank.

      The second way is more reliable. But before carrying out the procedure, wait until the motor and antifreeze have cooled down to avoid burns. Disconnect the coolant return hose from the expansion tank and lower it into a suitable, clean container. Instead, we connect a pump or compressor to the tank.

      Next, unscrew the cap of the tank and add coolant to the top. We pump the antifreeze with a pump until its level reaches the minimum mark. It is possible that all the air will be removed the first time, but it is better to repeat the operation one or two more times to be sure.

      3. Dirt on the radiator

      If the radiator fins are covered with dirt, the air will not be able to pass through them, it will go around the radiator, almost without heating, and there will be a cool draft in the cabin instead of heat. In addition, due to rotting debris, an unpleasant odor can appear.

      A thorough cleaning of the radiator will solve the problem.

      4. Internal pollution

      A blockage in the system due to internal contaminants can interfere with the circulation of antifreeze. The result - the engine overheats, and the stove does not heat up.

      Causes of clogging:

      • deposits on the walls due to the use of low-quality antifreeze or scale, if water was poured into the system,
      • sediment formed when mixing different types or brands of antifreeze,
      • pieces of sealant, which is used to eliminate leaks.

      A stove radiator clogged from the inside can be determined by touching the pipes connected to it. Normally, when the heating is on, both should be hot. If the outlet pipe is cold or slightly warm, then the passage of fluid through the radiator is very difficult.

      You can flush the system using special products or use a solution of citric acid for this, diluting 80 ... 100 g of powder in 5 liters of distilled water. For better dissolution of citric acid, it is better to pour it into a small amount of boiling water, and then dilute the resulting concentrate. If the system is very dirty, it may be necessary to repeat the operation.

      Sometimes flushing the radiator does not help. In this case, it will have to be replaced.

      5. Water pump problems

      If the pump does not pump antifreeze well through the system or does not pump it at all, this will quickly manifest itself as an increase in engine temperature and a decrease in heater efficiency. The problem must be solved immediately, as overheating is fraught with serious damage to the power unit.

      Usually the pump is driven mechanically using. It can wedge due to worn bearings or its impeller blades are corroded by overly aggressive additives that are sometimes found in antifreeze.

      In some cases, the pump can be repaired, but given the high criticality of this part, it is better to replace it periodically. Since access to the pump is rather difficult, it is advisable to combine its replacement with every second replacement of the timing belt.

      6. Fan not working

      If no air is blowing through the dampers, then the fan is not rotating. Try turning it by hand, it may jam, which will inevitably blow the fuse. It is also necessary to check the integrity of the wires and the reliability of the contacts at the points of their connection. It is possible that the motor burned out, then the fan will have to be replaced.

      7. Clogged air ducts, cabin filter and air conditioning radiator

      If the cabin filter is very dirty, then even at maximum speed, the fan will not be able to effectively blow air through the radiator, which means that the pressure of the air entering the cabin will be weak. The cabin filter should be changed once a year, and if the car is operated in dusty places, then more often.

      Air ducts should also be cleaned, especially if there is no cabin filter.

      In addition, the air blown by the fan also passes through the radiator of the air conditioner. It should also be inspected and cleaned.

      8. Stuck temperature control damper

      Thanks to this damper, part of the air flow can be driven through the stove radiator, and part can be directed past it. If the damper is stuck, the temperature control will be disturbed, cold or insufficiently warm air may enter the passenger compartment.

      The reason may be a faulty damper servo or flying cables and rods. Sometimes the electronic control of the heater or the temperature sensor in the cabin is to blame. You can't do without a good specialist.

      9. Faulty thermostat

      This device is actually a valve that remains closed until the coolant temperature rises to a certain value. In this case, the antifreeze circulates in a small circuit and does not enter the radiator. This allows the motor to warm up faster. When the heating reaches the response temperature, the thermostat will begin to open, and the antifreeze will be able to circulate through a large circuit, passing through the radiators of the cooling system and the stove. As the coolant heats up further, the thermostat will open more and at a certain temperature it will be fully open.

      Everything is fine as long as the thermostat is working. If it sticks in the closed position, the radiators will be excluded from the circulation of the coolant. The engine will start to overheat, and the stove will blow cold air.

      If the thermostat sticks and stays open all the time, warm air will begin to flow from the heater almost immediately, but the engine will warm up for a very long time.

      If the thermostat is stuck in the half-open position, insufficiently heated antifreeze may be supplied to the heater radiator, and as a result, the stove will heat poorly.

      The jamming of the thermostat in a partially or fully open position is manifested by the fact that the stove works well while driving in low gears, but when you turn on the 4th or 5th speed, the heater efficiency drops noticeably.

      A defective thermostat should be replaced.

      В интернет-магазине Kitaec.ua вы может приобрести радиаторы, вентиляторы и другие салона. Здесь также имеются детали для и других узлов и систем вашего автомобиля.

      How to avoid oven trouble

      Following simple rules will help to avoid problems with heating the car interior.

      Keep the radiator clean.

      Use high-quality antifreeze to prevent clogging of radiators and other elements of the system from the inside.

      Don't forget to change your cabin filter regularly. This is useful not only for the normal operation of the heater, but also for the air conditioning and ventilation system.

      Do not use sealant unless absolutely necessary. It can easily get inside and impede the circulation of antifreeze.

      Do not rush to turn on the stove immediately after starting the engine, this will slow down the heating of not only the engine, but also the interior. Wait until the engine warms up a little.

      To heat up the interior faster, turn on the recirculation system. When it becomes warm enough inside, it is better to switch to the intake air. This will help prevent fogging of the windows, and the air in the cabin will be fresher.

      And of course, you should check and prepare the stove for the winter before the onset of cold weather, then you won’t have to freeze. 

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