VAZ 2115 stove does not heat, diagnostics and repair

If the heater in the car does not work, especially in the cold season, there is a possibility of being left without a means of transportation, since in the cold you can simply freeze inside the car. In severe frosts, it is very difficult to clear the windshield of ice to ensure visibility, and with a non-working stove this becomes doubly problematic. You may not even be able to get to a service station.

But most often, if you know the operating principle, circuit and design of the VAZ-2115 stove, you can solve the problem on the spot yourself.

The design and principle of operation of the VAZ 2114/15 stove

The heating system of the VAZ 2114/15 is designed to heat the air entering the passenger compartment. Its design is the same in cars with injection and carburetor engines. The coolant heated by the engine flows from the cooling system into the heater radiator, which is blown by a fan. The flow of warm air created in this way enters the cabin through the air duct system. The intensity and direction of air flow is regulated using deflectors and dampers. The interior heating system of the VAZ 2114/15 can operate in several modes.

The VAZ 2114/15 stove is designed quite simply: 1 - assembled heater; 2 — protective casing; 3 - seal; 4 — front air duct; 5 — rear air duct; 6 — rear air duct; 7 — right nozzle; 8 — right side air duct; 9 — right side nozzle; 10 — intermediate body; 11 — central nozzle; 12 — draft of the windshield heating flap; 13 — heater control levers; 14 — control handle for the heated windshield damper; 15 — heater control handle; 16 — symbol plate; 17 — control handle for the foot heating damper; 18 — right air duct; 19 — interior heating air duct; 20 — heater control damper rod; 21 — heater valve control rod; 22 — heater valve; 23 - leg heating damper rod

Stove design

The VAZ 2114/15 stove consists of the following elements:

Fan.
Windshield defroster.
A distribution flap that directs air flow to the central and side deflectors, to the lower and upper parts of the cabin.
Control valve.
Stove radiator.
Duct that directs air flow to the legs.
Internal air duct.

The stove consists of a fan, dampers, radiator and air ducts. Blue and red colors indicate the flow of cold and hot air, respectively.

Lada 2115 2006, 76 l. With. — tuning

Cars for sale

Lada 2115 Samara, 2005

Lada 2115 Samara, 2004

Lada 2115 Samara, 2008

Lada 2115 Samara, 2011

Heater fuse and reasons for its failure

Often the cause of malfunction of most components and systems of a car is a blown fuse. The stove is no exception. Failure of a 30A heating system fuse causes the fan motor to stop and air to stop flowing into the cabin. In this case, find an element marked F7 in the fuse block and replace it. The new fuse should also be rated 30A. If the fan does not work after this, the problem should be looked for elsewhere.

Heater fuse F7 is located in the mounting block under the hood on the driver's side

It is often difficult to determine that it is the fuse that has blown. It can fail due to a short circuit in the electrical wiring, a malfunction of the electric motor, severe clogging of the cabin filter and in a number of other situations. The difficulty lies in the fact that fuse F7 is simultaneously included in the rear window heating electrical circuit and is responsible for the cigarette lighter, glove compartment lighting and headlight washer motor. If it fails, all these components will not work.

Major electrical failures of the heating system of the VAZ-2115

If no changes occur in the heating system at any position of the switch knob, then most likely the system motor is faulty (the brushes are worn out) or there is no voltage at the terminals. But also in this case there may be problems with the ignition switch or mounting block (fuse F4 has blown).

It is important for the proper operation of the car's heating system that there is no more than 3 ohms at the engine ground (installed under the hood).

If the heater works normally at maximum engine speeds, and problems arise only at low speeds, then the cause of the malfunction most likely lies in the speed switch button or additional resistors.

If you turn on the interior heating system and hear a noise and the heater is not blowing properly, this also indicates an engine problem. Malfunctions may include jamming of the impeller or armature bearings. Malfunctions can be eliminated by replacing components or, if necessary, lubricating them. But, as a rule, these actions have a short-term effect and the problem returns.

Over time, any equipment breaks down and requires repair. Therefore, the heating system is no exception here, and the least that needs to be done for preventive purposes is to at least carry out periodic visual inspections and diagnostics. Don’t forget that over time the system ages and wears out, so the older the car, the more it needs to be prepared for the heating season.

Why the stove does not work or does not heat the air

If the stove fails, it either does not work at all, or it works but does not heat the air. In the first case, first check the fan wiring, starting with fuse F7. If the fuse is blown, replace it. Then they check the relay, which may not turn on the first time or only when the engine is warm. In this case, the relay is replaced with a new one.

Then the serviceability of the electric motor is assessed. To do this, power is directly supplied to its contacts from the battery. If the electric motor starts to operate at maximum speed, then it is in good condition. Otherwise, it will need to be repaired or replaced.

The intensity of the air flow is adjusted using a resistor having two spirals with resistances of 0.82 Ohm and 0.23 Ohm. In the first mode, the current flows through both spirals, in the second - only through a spiral with a resistance of 0.23 Ohms, in the third - bypassing the spirals, that is, without resistance at all. If the resistor is faulty, the fan will only operate in the third mode at maximum speed (handle in the extreme right position). The problem is solved by replacing the resistor, which is located on the driver's side above the accelerator pedal.

If the resistor is faulty, the heater fan will only be able to operate at maximum speed.

If cold air enters the cabin, this may be due to:

Airlock. It could have formed when replacing the coolant, when the system was depressurized, or because there was insufficient amount of coolant in the system. To remove the plug, remove the heater radiator pipe, use a watering can to add antifreeze to the maximum and put the hose back in place. After starting the engine, coolant under pressure will displace the remaining air from the system.
Stove tap jammed. This happens if the tap was not initially opened all the way, and during operation, oxide and scale formed on the inner surface, preventing the normal circulation of the liquid. You can try to open the tap using pliers or immediately replace it with a new one.
The stove radiator is clogged. When using low-quality coolant, the radiator honeycombs may become clogged. The problem is solved by flushing or replacing the heat exchanger. The feasibility of washing is determined by the scale of contamination.
Installation of a low-quality radiator. In a defective product, the honeycomb may be incorrectly soldered. The radiator should be replaced.
Low pressure in the cooling system. If heat transfer increases at higher speeds, the pump needs to be replaced.
Low coolant level. It is necessary to check the level and add antifreeze if necessary.
Damage to the heater fan impeller. The impeller is carefully inspected and replaced if mechanical damage is detected.
Cabin filter dirty. If it is heavily polluted, the power of the electric motor will not be enough to pump warm air into the cabin. The filter is replaced with a new one.
Damage to the cylinder head gasket. If the cylinder head gasket is blown, white smoke will come out of the exhaust pipe. The problem is solved by replacing the gasket and dismantling the cylinder head.

If the stove is clogged, warm air will stop flowing into the cabin.

Diagnosis of heating system faults

Heating system malfunctions are accompanied by the following symptoms:

the fan does not work;
cold air enters the cabin;
the damper does not work;
there is a coolant leak;
the stove begins to make uncharacteristic sounds (whistles, hums, gurgles);
Steam or smoke appears from the heater ducts.

Why the stove does not work or does not heat the air

If the stove fails, it either does not work at all, or it works but does not heat the air. In the first case, first check the fan wiring, starting with fuse F7. If the fuse is blown, replace it. Then they check the relay, which may not turn on the first time or only when the engine is warm. In this case, the relay is replaced with a new one.

If the resistor is faulty, the heater fan will only be able to operate at maximum speed.

If cold air enters the cabin, this may be due to:

Airlock. It could have formed when replacing the coolant, when the system was depressurized, or because there was insufficient amount of coolant in the system. To remove the plug, remove the heater radiator pipe, use a watering can to add antifreeze to the maximum and put the hose back in place. After starting the engine, coolant under pressure will displace the remaining air from the system.
Stove tap jammed. This happens if the tap was not initially opened all the way, and during operation, oxide and scale formed on the inner surface, preventing the normal circulation of the liquid. You can try to open the tap using pliers or immediately replace it with a new one.
The stove radiator is clogged. When using low-quality coolant, the radiator honeycombs may become clogged. The problem is solved by flushing or replacing the heat exchanger. The feasibility of washing is determined by the scale of contamination.
Installation of a low-quality radiator. In a defective product, the honeycomb may be incorrectly soldered. The radiator should be replaced.
Low pressure in the cooling system. If heat transfer increases at higher speeds, the pump needs to be replaced.
Low coolant level. It is necessary to check the level and add antifreeze if necessary.
Damage to the heater fan impeller. The impeller is carefully inspected and replaced if mechanical damage is detected.
Cabin filter dirty. If it is heavily polluted, the power of the electric motor will not be enough to pump warm air into the cabin. The filter is replaced with a new one.
Damage to the cylinder head gasket. If the cylinder head gasket is blown, white smoke will come out of the exhaust pipe. The problem is solved by replacing the gasket and dismantling the cylinder head.

If the stove is clogged, warm air will stop flowing into the cabin.

Heater dampers don't work

The distribution of air flows throughout the cabin is carried out by dampers, which, in turn, are controlled using cables. When these cables fail, problems arise with directing the air flow to the windshield or to the foot area. In addition, the damper that blocks the flow of air from the street begins to work incorrectly. In this case, adjustment of the damper drives is required.

Such situations can arise even on a new car. Slightly warm air begins to flow from the lower, upper and side deflectors, and hot air begins to flow from the center console. This is due to the poor build quality. There are gaps between the joints of the air ducts and the dampers, which leads to warm air entering only from the center console and heating the panel from the inside.

The drive cable is always taut. Therefore, over time it bends, breaks off or stretches. In this case, it is necessary to adjust the damper drive, which is performed in the following order:

In the stove, we look for a bracket with which the cable sheath is held on the heater body.
A galvanized metal lever located on the left side is pulled back. This position corresponds to the maximum opening of the damper.
The length of the cable is tightened and adjusted. The long lever on the lever block in the extreme right position should open the damper completely.
After adjustment, the cable is securely fixed.

Video: stove repair using the example of a VAZ 2114

Why is antifreeze leaking from the stove?

A coolant leak in the heating system can occur from:

stove radiator;
stove tap;
stove pipes.

If a coolant leak occurs from the radiator, it is usually replaced with a new one. Repairs to restore tightness are usually complex and labor-intensive. In addition, if the radiator has been in use for a long time, its tubes become clogged with deposits and dirt, and, as a result, heat transfer decreases.

The valve opens and closes the coolant supply to the radiator, thereby regulating the heat in the cabin. Over time, it may begin to leak, as evidenced by the characteristic smell of antifreeze in the cabin, a puddle on the floor on the passenger side and a decrease in the coolant level in the expansion tank. The faucet cannot be repaired and in such cases is replaced entirely.

If the heater radiator starts to leak, it is usually replaced with a new one.

The cause of coolant leakage from the pipes is usually their wear - the rubber ages and cracks over time. When diagnosing a problem, you need to wipe the suspected leak areas with a rag and observe the outlet and inlet pipes on a warm engine. Worn hoses are always replaced with new ones.

The stove makes a hum, whistle, murmur

The cause of uncharacteristic sounds (whistle, hum, murmur, etc.) from the heater is usually a faulty electric motor. Lack of lubrication, contamination, wear of bearings and bushings - all this leads to the fact that the motor begins to whistle. It is removed, disassembled and cleaned, and the rubbing elements are lubricated. If the bearings are heavily worn, the motor will not make a whistle, but a hum. In such a situation, lubricant may not help, and the electric motor will need to be replaced.

Steam is coming from the stove

Sometimes steam starts coming out of the stove. The reason for this is a leak in the heater core. The leaking coolant hits the hot radiator housing and begins to quickly evaporate, and the smell of antifreeze appears in the cabin. To fix the problem, you will need to disassemble the stove and replace the heat exchanger.

Sometimes white steam comes from under the hood and enters the cabin. This happens when antifreeze gets on the hot manifold or exhaust system pants. In this case, you will need to find the location of the leak and fix it. The most common cause is damaged pipes.

Heater dampers don't work

The drive cable is always taut. Therefore, over time it bends, breaks off or stretches. In this case, it is necessary to adjust the damper drive, which is performed in the following order:

In the stove, we look for a bracket with which the cable sheath is held on the heater body.
A galvanized metal lever located on the left side is pulled back. This position corresponds to the maximum opening of the damper.
The length of the cable is tightened and adjusted. The long lever on the lever block in the extreme right position should open the damper completely.
After adjustment, the cable is securely fixed.

Video: stove repair using the example of a VAZ 2114

Possible heater malfunctions

If the stove does not work, this indicates that the heating system has a malfunction.

The following breakdowns are typical for VAZ 2115 cars:

coolant leakage due to a leak in the system;
obstruction of antifreeze may be due to the presence of an air lock, which usually appears as a result of the accumulation of dirt and deposits in the system pipes.

If the heater does not work on a VAZ 2115, then this may primarily be due to an antifreeze leak. It is not so easy to notice such a problem, since the heater radiator itself is located behind the center console and is hidden from the driver’s eyes. Signs of a consumable leak include a decrease in antifreeze in the tank, as well as the appearance of wet spots under the driver's mat. As a rule, coolant entering the cabin is accompanied by the appearance of an unpleasant odor, and a greasy film may form on the windshield of the car.

If the heater does not blow due to obstruction of antifreeze, then such a malfunction is usually associated with the use of low-quality consumables. Or dirt getting into the system. In addition, a traffic jam may appear due to long-term use of the device. One of the main symptoms is cold air flow from the air ducts. To check the breakdown, you should touch the input and output lines - if there is an air lock, the first will be hot and the second cold (the author of the video is the channel In Danilych's garage).

Replacing and connecting the stove

Installing a new heater radiator is done in the reverse order. When installing rubber hoses, it is recommended to treat them with sealant. When connecting electrical connectors, use the markings applied during disassembly.

After assembly, coolant is poured into the system. To prevent an air lock from forming, remove the hose from the throttle assembly after loosening the clamp. Antifreeze should be poured into the expansion tank slowly, observing the disconnected hose. As soon as coolant flows out of it, the hose should be put back on the fitting and tighten the clamp. If everything is done correctly, the operation of the stove will not cause any complaints.

When installing a new heater radiator, it is recommended to pre-treat the pipes with sealant

Video: dismantling the VAZ 2114 stove

The operation of the stove is based on the following principle

The cooling and heating system works the same on almost all VAZ car models. The heater is turned on using a regulator located in the car itself; antifreeze is supplied to the radiator. Its temperature after warming up reaches more than 80 degrees. After which the fan starts working, operating at one of 3 speed modes.

The fan begins to create a directed air flow. It moves from the outside of the heating system into the interior of the car. Using control flaps, the driver selects heating zones, there are three in total: on the feet, on the windshield and in the car interior.

The key element of a car's heating system is the fan, and if it fails, the heating will be lost. Without it, hot air will not enter the cabin, and to heat the interior of the VAZ-2115, it will take not a couple of minutes, but a couple of hours.

Fan motor repair

If the electric motor malfunctions, it should first be removed and then the feasibility of repair should be determined. It is necessary to evaluate the condition of the brushes, armatures, windings, and check the integrity of the wire insulation. The contact area of the brushes on the armature can be cleaned with zero grade sandpaper. You should also pay attention to the bushings and bearings - clean the rubbing parts from dirt and apply lubricant (for example, Litol). All elements with signs of wear must be replaced.

When installing a new heater radiator, it is recommended to pre-treat the pipes with sealant

Heater radiator repair

Usually, if mechanical damage is detected, the stove radiator is replaced with a new one. However, some car owners try to repair cracks and holes using soldering. A copper radiator is quite easy to solder, and it is much easier to restore than an aluminum one. To repair an aluminum heat exchanger, you will need special flux and tinning solder, as well as a powerful soldering iron. The damaged area is first cleaned of dirt and degreased. Then flux and solder are applied to it with a soldering iron. After soldering, it is recommended to check the radiator under pressure to make sure there are no leaks.

Cleaning and flushing the radiator of the VAZ 2114/15 stove

You can increase the efficiency of the stove by cleaning and flushing the radiator. The procedure can be performed without dismantling the radiator or with dismantling it. In the first case, you will need to remove the outlet and inlet pipes from the heater and pour a cleaning solution into it. Citric acid, plumbing cleaners (for example, “Mole”), etc. are used as such a solution. Then the radiator is washed with running water and coolant is added. You can clean the radiator better by removing it from the car. This will allow you to wash it not only from the inside, but also from the outside, removing dirt between the honeycombs. Washing is usually carried out with running water.

If after performing these procedures the stove does not work better, the radiator must be replaced.

Introduction

Almost all front-wheel drive vehicles of the domestic manufacturer (VAZ) are equipped with high-quality stove heaters that will not allow passengers and the driver to freeze even in severe frost. However, despite this circumstance, it happens that the stove blows cold air. There can be many reasons why VAZ cars are not warm enough during the cold season.

Cold air can only appear at idle, but at the same time, during active movement, the car interior will warm up well. Therefore, if the VAZ-2115 stove does not heat well, you should start solving the problem by troubleshooting, sequentially diagnosing all components of the car.