Comprehensive modification of the stove/heater of Niva 4x4 (VAZ 2121, 2131)

VAZ-21213 (Niva). Removing and installing the heater

EXECUTION ORDER

1. Move heater valve 17 control handle 6 all the way to the right and drain the liquid from the engine cooling system. 2. Disconnect the ground cable from the battery. 3. Remove the fastening screws, remove the instrument panel shelf and the radio panel, and disconnect the electrical wires. 4. Loosen the clamps and disconnect the rubber hoses for supplying and discharging fluid from pipes 16 of the heater. 5. Unscrew the two mounting bolts inside the engine compartment and remove the heater radiator pipe seal. 6. Loosen the bolt of the bracket securing the flexible rod shell on the tap and remove the rod from the tap. 7. Remove the heater fan motor switch and disconnect the wires from it. 8. Remove the four spring holders and the fan casing 18 assembled with the electric fan. 9. Remove the instrument panel panel, through the opening for it in the panel, loosen on bracket 7 the screws of the brackets of the flexible rods of the air inlet cover 12 and the damper 3 of the windshield heating air duct. Remove the rods from the control levers. 10. Unscrew the nuts securing the radiator casing 15 to the air inlet box 14, disconnect the ground wire secured under one of the nuts, remove the casing and the air inlet box. 11. Install the heater in reverse order. Pay attention to the correct position of the sealing gasket between the radiator casing and the body, and to the reliability of tightening the rubber hose clamps. 12. After installing and connecting the hoses, fill the engine cooling system with liquid and check the tightness of the connections.

VAZ-21213 (Niva). Disassembly and assembly of the heater

Interior ventilation

Outside air can enter the vehicle interior:

• through open door windows;
• through nozzles 2 (Fig. 1-6) for blowing the windshield, if you move distribution lever 8 and lever 7 for controlling the air supply hatch cover to the right;
• through the side nozzles 1 for blowing the door windows, if you move lever 7 to the right and lever 8 to the left;
• through holes 9 of the heater casing into the driver's and front passenger's foot area, if you open the heater cover with lever 10 and move lever 7 to the right;
• through the central nozzles 5 directly from the air supply box when the car is moving, if the regulators 3 open the nozzle flaps (summer airflow). By moving lever 4 in the horizontal and vertical directions, the direction of the air flow from the nozzle changes.

In the middle position of lever 8 and in the right extreme position of lever 7, air will flow through nozzles 1 and through nozzles 2.

If the car is moving at low speed, you can increase the amount of incoming air by turning on the electric heater fan with switch 12.

Improvement No. 1. We take air from the cabin

The main disadvantage of the Niva heater is that all the air into the heater radiator comes from the street, and when the air intake flap is closed, air circulation and heating stop completely. To eliminate this drawback, I disassembled the heater (I had to drain some of the antifreeze and disconnect the heater radiator pipes), and in the side wall of the heater housing, opposite the wall where the radiator tubes exit, I made a hole in the shape of a rectangular trapezoid. I did it in such a way that there was 1.5-2 mm of the body wall left to the boundaries of the plane in which I made the hole, and 6-8 mm from the side of the stiffener for attaching the petal valve. I made the hole using a drill, marked it, drilled along the contour of the small diameter holes, then connected the holes using a knife, then filed the edges of the resulting hole, giving it its final shape. The area of ​​the resulting hole was approximately 25 square centimeters. It is through this hole, when the heater air intake flap is closed, that air is drawn from the passenger compartment.

Since the salon is a closed space, air circulation occurs in a closed circle, and the warming up air of the salon, passing through the heater radiator, becomes increasingly hotter at the exit. Despite the small size of the hole, due to the absence of a supply of icy air from the street, the time for warming up the interior to a comfortable temperature and melting icy glass is reduced by 4-5 times, and it is possible to achieve a comfortable temperature even in severe frost.

To prevent cold air from entering the cabin through the hole when the air intake flap is open and the heater fan is turned off, a petal valve is installed on the hole on the inside of the heater housing, which does not interfere with air intake from the cabin. The petal valve is a rubber band cut from a car chamber (preferably from a truck), 1.5-3 mm thick, in the shape of a hole, but slightly larger, and attached to a bolt in such a way that it can freely bend inside the heater body, opening the access of air from interior, and fit snugly against the wall of the heater housing, blocking the hole for the passage of cold air into the cabin, past the heater radiator.

Interior heating

To heat the interior and protect the windshield, door windows and rear window from fogging and freezing:

• move levers 6 and 7 to the right;
• set lever 8 to the middle position;
• open the heater cover with lever 10;
• turn on switch 11 heated rear window;
• If necessary, turn on the electric heater fan with switch 12.

Warm air will be directed both to the driver’s and passengers’ footwells and to the windshield and front door glass. For faster heating of only the windshield, close the heater cover with lever 10 and move lever 8 to the right.

Do-it-yourself modification of the stove on Niva 21213 is necessary if the car’s heating system malfunctions. There is no point in delaying this, because uneven thermal regulation leads to foggy windows or icing. In any of these cases, the view of what is happening on the road deteriorates. The malfunction causes wear of individual elements of the device or manufacturing defects.

Comprehensive modification of the stove/heater of Niva 4x4 (VAZ 2121, 2131)

Having set out to increase the efficiency of my car's heater, I re-read the available methods on the forums, and realized that these methods have some drawbacks that did not suit me. For example, installing a fan from a VAZ 2108 allows you to increase the air flow through the heater and blower nozzles, but this air is taken from the street, it is icy, and therefore the interior begins to warm up only after the engine has completely warmed up. In addition, this method requires significant modifications to the design of the heater, as well as the cost of purchasing a fan. Next, I’ll tell you how to modify the stove on the Niva with your own hands without investment and in a short time.

Fault Diagnosis

The stove supplied as standard will need to be modified for preventive purposes. The procedure will not take much time, but it will prevent many problems in the future. Driving experience suggests that the first severe frosts will undermine the “health” of the device. The list of main weaknesses is as follows:

• the optimal operating temperature range for model 2121 is from -5 to +10°C;
• inability to warm up the air in the cabin if outside is -8°C or lower;
• when the blowing power increases, the temperature does not increase;
• When driving in 2nd gear, the noise from the Niva's stove becomes significant.

That is why it is better to take the necessary measures in advance. The driver has few alternatives. On the one hand, everything remains in its place. The heating device is used at minimum power. During mild winters this is still tolerable, but with the onset of real cold weather the conditions will become unbearable. On the other hand, it's easy to spend a few hours rectifying the situation.

Further developments proceed as follows. If the heating in the car is running at ½ power, you can limit yourself to minor repairs. The main thing is to make sure that there are no noises or extraneous knocks, otherwise the Niva 21213 should immediately go for a technical inspection.

The presence of an unpleasant sound indicates the need to replace the device. A specialized retail network offers ready-made options for heating mechanisms for Niva. If desired, it can be assembled independently.

Improvement No. 3. Installing the grille on the air intake

When disassembling the heater, a large number of tree leaves and insect remains were found in the air intake casing and in the honeycombs of the heater radiator grille, which also reduced the efficiency of the heater. Therefore, after cleaning and flushing the heater core, I took measures to prevent the radiator from clogging.

To do this, I bent a wire frame to the size of the air intake inlet, covered it with a nylon mesh with a 1x1 mm cell, and installed it at the bottom of the rubber seal of the air intake inlet. It was perfectly fixed there in the fold, like an accordion, without additional fastening.

All work to modify the heater took me about 4 hours of time and did not cost a penny of additional costs. Unfortunately, during work I didn’t think to take a photo, but from the attached drawing and picture everything should be clear. I'm happy with the result, now the stove heats better.

Technical details of the procedure

The efficiency of the new heating system on Niva will be determined not by the cost of the purchased parts, but by their quality. To operate, you will need the following elements: a car resistor, a figure-eight heater and a “snail”. It is a mistake to believe that only “original” spare parts are suitable for repairing a heating device. The main requirement is technical compatibility.

If in doubt, a drawing of the heating system will provide clarity. The further procedure is as follows:

Cut a new mounting hole. This is done carefully, because the reliability of the heating system’s operation depends on the quality of the preparatory process. It is recommended to place the engine as low as possible in the air duct, otherwise the device will rest against the hood. This should not be allowed to happen, otherwise the stove fan will not last long.

The heating system of a new model is checked by test switching on. It is recommended to switch modes smoothly. The device must remain on each of them for at least 5-7 minutes. The driver’s task is to make sure that the operation of the system is not accompanied by extraneous noise and vibration.

Original parts vs analogues: practical advice

As mentioned earlier, such a choice does not affect the quality of the heating system. At the same time, car mechanics make several reservations. For those who plan to use VAZ stoves, it would be useful to check the power system. It is different for some modifications. That is why all actions are consistent with the drawings.

It is permissible to use the VAZ 2108 heater, provided that two recommendations are followed. Firstly, the mounting socket is 1-2 cm larger than the size of the device. The additional area will reduce the vibration impact. Secondly, the switch is installed taking into account the specifics of the VAZ heating system. You will have to tinker less when minor modifications to the system are needed.

The ventilation system is updated in 1-2 hours, depending on the degree of wear of the engine.

If the factory-installed “snail” has no signs of physical wear, you only need to replace the heater “engine” itself.

It’s worse if the factory equipment of a Chevrolet model has manufacturing defects. A complete replacement of the device is recommended. This will save time.

The operation of the heating system determines the comfort and safety of driving. The driver constantly monitors the system's performance. If extraneous noise appears, it is necessary to urgently carry out a technical inspection.

Heater diagram

1 – damper; 2 – electric fan casing; 3 – fan electric motor; 4 – impeller; 5 – heater radiator; 6 – radiator inlet pipe; 7 – radiator outlet pipe; 8 – radiator casing; 9 – air duct damper; 10 – air duct box; 11 – air duct for heating the windshield; 12 – central deflector damper; 13 – central deflector; 14 – crane control lever; 15 – control lever for the windshield heating flap; 16 – air duct damper control lever; 17 – control lever bracket; 18 – windshield heating flap; 19 – windshield heating damper cable.

Heating and ventilation system components

The heater fan (ME-255) supplies air to the passenger compartment through air ducts. Its rotation speed is controlled by a three-position switch on the panel.

An additional resistor is designed to reduce the fan rotation speed (intermediate rotation speeds).

The heater radiator is installed in the passenger compartment under the panel in a plastic case and serves to transfer heat to the interior.

The heater valve is installed at the inlet of the heater radiator and serves to regulate the flow of antifreeze that passes through it.

The damper control levers serve to distribute air flows that are directed into the cabin, as well as to control the heater tap.

The design of the heater has a number of disadvantages, for example, strong fan noise, as well as its low performance. We'll talk about this and other problems in the improvements section.

Keywords: Niva stove | Niva air ducts

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The ventilation system of the VAZ-21213 car is supply and exhaust.

When the car is moving, air is forced into the cabin by natural pressure through the air intake slots on the hood and is sucked out through the holes in the rear roof pillars

To increase air circulation when driving, you can lower the front door windows, and at low speeds, turn on the electric fan.

Air flows in the cabin are distributed by air ducts located inside the dashboard.

Air enters the windshield through the upper slot-like nozzles on the instrument panel, onto the side windows through the side and, partially, central nozzles (with air flow guides), and to the feet through the holes in the heater casing (with the lid folded back).

To control the distribution of air flows, use the middle and lower levers on the center console of the instrument panel, as well as the guides of the central nozzles and their regulators.

The heating system is liquid, combined with the engine cooling system.

The heater radiator is installed in the instrument panel console in a plastic casing and sealed around the perimeter with foam tape.

Air heating depends on the degree of opening of the valve that regulates the flow of liquid through the radiator.

The valve is installed at the radiator inlet and is controlled by the upper lever on the center console.

The ME-255 fan electric motor is a commutator motor, DC, with excitation from permanent magnets.

The fan speed is controlled by a three-position switch on the instrument panel.

Depending on the selected speed, the electric motor is connected to the vehicle’s on-board network directly (high frequency) or through an additional resistor (low frequency).

The rotational speed of the electric motor shaft with an impeller at a voltage of 12 V and an air temperature of 25±10°C is 3000±150 min –1.

Current consumption at maximum rotation speed is no more than 4.5 A. The fan impeller is fixed to the electric motor shaft.

The electric motor cannot be repaired; if it fails, it must be replaced.

How to upgrade the Niva-21213 stove

If you are the owner of a Niva-21213 and are in love with this vehicle, then you are unlikely to give it up if you find some technical defects in it. In principle, this is absolutely correct; you can remain faithful to your “iron horse”, and if defects are identified, try to eliminate them yourself.

Niva-21213, indeed, needs some of your intervention; tuning the Niva stove will not be superfluous at all.

https://www.youtube.com/watch?v=3ch3Fh8Xx38

In the summer, you won’t be able to notice any inconvenience, but with the onset of cold weather, you definitely won’t be able to do without enhanced wardrobe equipment in the form of cotton pants and a jacket.

You don’t want to constantly feel like a “tanker”, so most owners of this car decide to roll up their sleeves and modify the stove of their own Niva. By the way, the same problems are inherent in another domestic model - the UAZ, the owners of which are also actively searching for what to do to improve the performance of the stove.

The process of refining the heating system

It is useful to note that modification of the VAZ-2121 stove is not accompanied by high problems. Even a car enthusiast who does not have special technical and repair skills can eliminate such technical defects.

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In addition, modification of the Niva-2121 stove may involve performing a variety of actions, including the most basic ones.

Heating in your car can be improved by even just slightly upgrading the air ducts. If you want to radically improve the heating system and increase comfort, then, of course, you will have to tinker a little more.

Air duct modernization

Unfortunately, if you carefully examine the air ducts that your Niva is equipped with, you will be horrified at how it was possible to install so many cracks in it. Is it possible to expect good heating with such a design?

The answer, of course, is simple, since all the heated air is dispersed under the dashboard, and the interior is heated according to the residual principle.

However, it’s good when a problem is so easily identified, then solving it is much easier. Upgrading the air duct involves applying silicone glue to all joints.

Be prepared for the fact that performing such actions is sometimes quite difficult, since not all places have unobstructed access. You still have to get used to it and apply silicone glue to all the joints.