How to properly remove the evaporator of a Bosch refrigerator: disassembling NoFrost and the drip system

Removing the evaporator in the refrigerator Bosch —a task faced in the event of serious breakdowns: from freon leakage to replacing a burnt-out defrost heating element. Unlike surface cleaning, removing this unit requires disassembling the internal casing, working with the refrigerant and strictly following the sequence of actions. Errors here are fraught not only with repeated breakdown, but also depressurization of the systemwhich will cost 3-5 times more than the initial repair.

In this article we will analyze two scenarios: dismantling the evaporator in models with the system NoFrost (for example, Bosch KGE39XW2AR or KAN92VI30R) and in drip refrigerators (series KGN39XL30, KGV36XW20R). We will pay special attention differences in the evaporator mounting to the rear wall, the nuances of disconnecting the tubes and diagnosing related faults. If your model is equipped LowFrost or VitaFresh, check the compatibility of the instructions - these systems often combine elements of both types.

We warn you right away: the procedure requires skills in working with tools, understanding of the principles of the refrigeration cycle and, ideally, the presence vacuum pump for refilling freon. If you have never dealt with soldering copper tubes or gage manifolds, it is better to contact a specialist. However, for those who are ready to take the risk, we have prepared the most detailed guide with photographs of key stages and a table of tool compatibility.

Preparation: tools and safety measures

Before you begin disassembly, collect the necessary equipment. Without some tools, it is without damaging the circuit impossible to remove the evaporator. Here is the minimum set:

• 🔧 Socket wrenches (8 mm, 10 mm) - for unscrewing the fastenings of the compressor and condenser.
• 🔨 Slotted and Phillips screwdrivers (including a short one for working in hard-to-reach places).
• 🔥 Gas torch or blowtorch —for disconnecting copper tubes (only when replacing the evaporator!).
• 🧤 Heat-resistant gloves —the temperature of the tubes during soldering reaches 200°C.
• 🛠️ Vacuum pump (optional, but highly desirable for refilling freon).
• 📏 Valnier calipers - for measuring the diameter of the tubes when purchasing a new evaporator.

If your model Bosch uses aluminum evaporator (relevant for some lines after 2018), soldering with standard solder will not work - you will need a special flux and low-temperature solder. Check the type of material by the marking on the evaporator itself or in the documentation.

⚠️ Attention: Working with freon requires a ventilated room! Refrigerant vapors (even modern R600a or R134aat high concentrations cause dizziness and nausea. If the refrigerator was in the kitchen, move it to the garage or to the balcony.

Also prepare a container to collect condensation (up to 1-1.5 liters of water will leak out during defrosting) and plastic film to protect the floor. Some craftsmen recommend take a photograph of the location of all tubes and sensors before starting disassembly - this will simplify reassembly.

Step 1: Turning off and defrosting the refrigerator

The first stage seems obvious, but many miss important details. Simply unplugging the plug from the socket is not enough - you need completely discharge the capacitors a compressor to avoid electric shock. To do this:

1. Disconnect the refrigerator from the mains.
2. Wait for the fan to stop (in models NoFrost it can scroll for another 1-2 minutes).
3. Press and hold button Super Cooling (if available) 10 seconds - this will release the residual charge.
4. Leave the doors open for 12-24 hours for complete defrosting.

In refrigerators with NoFrost ice accumulates not on the walls, but inside evaporator, behind the plastic panel. To speed up the process, you can use hairdryer at minimum poweraimed at the ventilation holes. Under no circumstances try to pick off the ice with a knife - this will damage the aluminum fins of the evaporator!

⚠️ Attention: If your refrigerator Bosch is equipped with a function VitaFresh with a separate cooling zone, you also need to defrost the main one compartment, and second circuit (if it exists). Ignoring this step will lead to icing of the new evaporator within a week.

After defrosting, thoroughly wipe all surfaces with a dry cloth. Humidity inside the case accelerates corrosion of metal parts and can cause a short circuit when turned on.

Step 2: Dismantling the internal panels

The design of panels in refrigerators Bosch depends on the cooling system. Let's consider both options.

For models with NoFrost (for example, KGE39XW2AR, KAN92VI30R)

In systems NoFrost the evaporator is hidden behind the rear panel of the freezer. To get to it:

1. Remove all shelves and drawers from the freezer.
2. Unscrew the screws holding the plastic panel (usually 4-6 pieces under decorative plugs).
3. Carefully pry the panel with a slotted screwdriver - it is held on by plastic latches. Do not use excessive force so as not to break the fasteners!
4. Under the panel you will see fan, TEN defrosting the evaporator itself (aluminum or copper radiator with fins).

In some models (for example, Bosch KGN39XI40), the panel can be glued around the perimeter with double-sided tape. In this case, heat the edges with a hairdryer at the minimum temperature so that the glue softens.

For drip models (for example, KGV36XW20R, KGN39XL30)

In drip refrigerators, the evaporator is located behind the back wall of the main chamber. Disassembly algorithm:

1. Remove all products and shelves.
2. Remove the top cover of the refrigerator by unscrewing the screws on the back (they may be hidden under stickers).
3. Detach the plastic panel covering the evaporator. It is attached with latches on the sides and one screw at the bottom.
4. Under the panel you will find a plastic box with a drainage hole it also needs to be removed to gain access to the evaporator.

Inspect carefully state drainage tube. If it is clogged with ice or dirt, this could cause the evaporator to fail due to overheating. Clean the tube with wire or rinse with warm water.

What to do if the screws do not unscrew?

If the screws are “stuck” or have torn splines, use the following technique:

1. Heat the head of the screw with a soldering iron (do not overheat the plastic!).

2. Use a self-tapping screw extractor or fine-nosed pliers.

3. As a last resort, drill out the self-tapping screw with a drill, but be careful - freon pipes may pass under the panel!

Step 3: Disconnecting electrical components

Before touching the evaporator, you must disconnect all electrical connections. In refrigerators Bosch this is:

• 🔌 Temperature sensor (usually located next to the evaporator, attached to a clip).
• 🔥 Defrost heating element (in models NoFrost - under the evaporator, in drip models - maybe missing).
• 🌀 Fan (only in NoFrost, mounted on 2-3 screws).
• 📶 Control wires (go to the board, usually in a harness with connector).

To avoid mixing up the wires during reassembly, mark them with tape or take photographs. Pay attention to color marking:

In models with LowFrost there may be an additional frost sensor (usually blue or light blue). It should not be confused with the main thermostat! If you accidentally damage this sensor, the refrigerator will turn on randomly or will not start at all.

⚠️ Attention: In refrigerators Bosch after 2020, some connectors have lock against incorrect connection (asymmetrical notches). Do not force the connection - if the connector does not go in easily, turn it over.

Step 4: Removing the evaporator

This is the most critical stage. Depending on the type of refrigerator, the process will differ.

For NoFrost systems

The evaporator is NoFrost attached to the back wall of the freezer and connected to the freon circulation system by two copper tubes: input (from the compressor) and output (to the capacitor). To remove it:

1. Unsolder the tubes from the evaporator, having previously cut them with a pipe cutter. Leave a margin of 10-15 cm for subsequent soldering.
2. Unscrew the evaporator mounting bolts (usually 4 pieces in the corners).
3. Carefully remove the evaporator along with the fan and heating element (they can be mounted on the same frame).

In models Bosch with the TwinCool system (two independent circuits) will have to dismantle both evaporators - for the refrigerator and freezer compartments. Their tubes are often intertwined, so mark them with a marker before soldering.

For drip systems

In drip refrigerators, the evaporator is usually glued to the back wall or secured with plastic clips. Removal algorithm:

1. Remove the foam insulation around the evaporator (it can be glued or held on with Velcro).
2. Disconnect the drainage tube from the bottom of the evaporator.
3. Heat the glue around the perimeter of the evaporator with a hairdryer (temperature not higher than 60°C, so as not to damage the plastic).
4. Pry up the evaporator with a spatula and remove it from the base.

In some models (for example, Bosch KGV36XW20R), the evaporator may be soldered into a plastic case. In this case, you will have to cut the body with a hacksaw for metal, and after replacing it, glue it with epoxy resin.

Step 5: Diagnosis and replacement of the evaporator

Before installing a new evaporator, inspect the old one for damage:

• 🔍 Corrosion —rusty spots on the copper tubes indicate a leak freon.
• ❄️ Ice plugs —if the ice has formed unevenly, the capillary tube may become clogged.
• 🔥 Darkening of the heating element —a sign of overheating due to a faulty thermostat.
• 💧 Oil stains indicates that compressor oil has entered the system (flushing is required).

If you find a freon leak (usually manifested as oily spots on the tubes), you will have to recharge the system. To do this:

1. Connect manometric manifold to the service port (usually located on the compressor).
2. Pump out the remaining freon with a vacuum pump (minimum 30 minutes).
3. Fill the system with new refrigerant (the type is indicated on the nameplate of the refrigerator).

For models Bosch with R600a (isobutane) charging requires special care - this gas is explosive! Work away from open flames and sparks.

⚠️ Attention: If you are replacing the evaporator with a non-original one, check the compatibility by thermal power (BTU) and pipe diameter. A discrepancy will lead to increased load on the compressor and its rapid failure.

Step 6: Reassembly and testing

Assembling the refrigerator is done in the reverse order, but there are several critical points:

1. When soldering tubes, use flux for copper and avoid overheating - temperatures above 250°C destroy the metal structure.
2. Before filling with freon, check the system for leaks using nitrogen test (pressure 15-20 bar).
3. Make sure that the drain tube is not pinched or has any creases - otherwise condensate will accumulate in chamber.
4. After assembly, turn on the refrigerator in mode Super Cooling for 2 hours, then check the temperature in the chambers.

If, after switching on, the compressor runs without stopping or does not cool in the chamber, the following problems are possible:

• 🔄 Lack of freon —required refueling.
• 🔌 Temperature sensor not connected —check the connectors.
• 🌀 Clogged capillary tube —needs cleaning or replacement.
• ⚡ The control board is faulty — diagnose with a multimeter.

In models with NoFrost after replacing the evaporator, it may be necessary fan calibration. To do this:

1. Turn on the refrigerator.
2. Press and hold the button Fridge (or Freezer, depending on the model) for 10 seconds.
3. Wait for the sound signal - this means that the system has entered test mode.
4. Check the operation of the fan manually (it should turn on at full power).

FAQ: Frequently asked questions about replacing the evaporator

Is it possible to replace the evaporator without soldering?

In most cases, no - the evaporator tubes are soldered to the freon circulation system. However, some models (for example, Bosch KIN86AF30R) are used detachable fittings (type Valvex), which allow you to disconnect the tubes without soldering. Check this in the documentation for your model.

How much does a new evaporator for Bosch cost?

The price depends on the model and type of system:

• For NoFrost: 8,000–15,000 ₽ (original) or 4,000–7,000 ₽ (analogue).
• For drip systems: 5,000–10,000 ₽.
• For models with VitaFresh: up to 20,000 ₽ (due to the complex design with two circuits).

Buy only from authorized dealers Bosch or trusted suppliers of spare parts - fakes often have inappropriate tube diameters.

How to check that a new evaporator is working correctly?

After installation:

1. Turn on the refrigerator in mode Max Cool.
2. After 2 hours, check the temperature in the freezer - it should not be higher than -18°C.
3. Listen to the operation of the compressor: it should turn off periodically (20-30 minute cycle).
4. Inspect the back wall for the presence of frost - there shouldn't be any, in drip systems a thin layer is acceptable. NoFrost It should not be there; in drip systems a thin layer is acceptable.

If something goes wrong, turn off the refrigerator and check tightness soldering and connecting sensors.

What to do if after replacing the evaporator the refrigerator does not freeze?

There may be several reasons:

• Freon leak —check the soldering with a soap solution (bubbles will appear).
• Clogged capillary tube —nitrogen purge is required.
• The compressor is faulty —measure the resistance of the windings (should be 20-40 Ohms).
• Failure control board —try resetting the settings (turn off the refrigerator for 10 minutes, then turn it on).

The most common mistake is insufficient evacuation of the system before refueling. Repeat the procedure with a vacuum pump (at least 30 minutes).

Is it possible to clean the evaporator without removing it?

Yes, but only in drip systems. To do this:

1. Defrost the refrigerator.
2. Remove the back panel (as described in Step 2).
3. Wash the evaporator with warm water and detergent (for example, Loc from Amway).
4. Dry with a hairdryer (cold air!).

C NoFrost cleaning without dismantling is impossible - access to the evaporator is blocked by the fan and heating element. A vacuum cleaner or brush will not help here.