Bosch refrigerator works, but does not freeze: reasons and what to do

Your refrigerator Bosch is humming, the light inside is on, and the compressor is running non-stop - but the freezer has stopped freezing food? Or, conversely, does the motor turn on for a few seconds and immediately turn off? This situation is typical for models KGE36, KGN39, KAN92 and other series of the brand. The reason does not always lie in a serious breakdown - sometimes the problem is solved by simple adjustment or cleaning.

In this article we will look 7 most common reasonswhy The refrigerator Bosch does not freeze, although outwardly it seems to be working. You will learn how to independently diagnose a malfunction, when you can do without a technician, and in what cases delaying repairs is dangerous (for example, if there is a freon leak). We will also give step-by-step instructions for popular models and warn against typical mistakes that aggravate the breakdown.

⚠️ Important: If your refrigerator Bosch was produced before 2015, some technical solutions (for example, type refrigerant or evaporator design) may vary. Check the model in the documentation or on the nameplate inside the camera.

1. Incorrect temperature settings

The first thing to check is refrigerator operating mode. In 30% of cases, the problem lies in accidentally changed settings. For example, models Bosch KGE36 and KGN39 have a function "Vacation" (Holiday Mode, when activated, the freezer is turned off and the main compartment maintains +15°C. Also, users often confuse the adjustment scales: in some refrigerators Bosch 1 is maximum cold, and 7 is the minimum.

How to check:

• 🔍 Inspect the control panel. If the indicator Holiday or Vacation is on, press and hold the button Super (or Eco) for 3 seconds to turn off the mode.
• 🌡️ Make sure the freezer temperature control is set to on −18°C (or position 3–4 on the mechanical thermostat).
• ❄️ On models with NoFrost check whether the function SuperFreeze is activated - it may block normal operation if enabled for longer than 72 hours.

If the settings are correct, but the freezer still does not work, proceed to the following steps. Exception: in refrigerators Bosch Serie 8 with electronic control, the settings may fail after a power surge - a reset to factory settings is required (instructions below).

2. Clogged drainage system or fan

In refrigerators Bosch with a system NoFrost (models KGN39, KAN92 etc.), a fan is responsible for the freezer, which drives cold air through the chambers. If it is blocked by ice or debris, the freezer compartment will stop cooling even though the compressor is running. Also clogged drainage hole can lead to icing of the evaporator and stopping air circulation.

Signs of a problem:

• 🔊 The refrigerator hums louder than usual, but no cold comes in.
• ❄️ On the back wall of the freezer you can see a “coat” of ice.
• 💨 Cold air is not blowing from the ventilation grilles.

How to fix:

1. Unplug the refrigerator and defrost it at least 12 hours (in models NoFrost ice may be hidden behind the panels).
2. Remove the back cover of the freezer (in most models it is secured with latches or screws).
3. Check fan blades - they should rotate freely. Remove ice and debris.
4. Clean the drain hole (located under the evaporator) using a syringe with warm water.

Unplug the refrigerator|Defrost 12+ hours|Remove the back panel of the freezer|Check the fan for ice/debris|Clean the drain hole-->

⚠️ Attention: Do not use sharp objects to remove ice from the evaporator - this can damage the tubes and cause freon leakage. In models Bosch Serie 6 and higher, the evaporator is coated with a special compound that is easy to scratch.

3. Failure of the thermostat or temperature sensor

If the refrigerator Bosch turns on for a few seconds and immediately turns off, or, conversely, works without stopping, but does not freeze - The thermostat or sensor is to blame. Modern models (for example KGN39XW20R) use an electronic sensor that transmits data to the control board. If it malfunctions, the module receives incorrect signals and incorrectly regulates the operation of the compressor.

How to diagnose:

To check the temperature sensor in models Bosch Serie 8:

1. Unplug the refrigerator and remove the lid in the freezer (usually it is plastic, fastened with clips).
2. Find the sensor - it looks like a small plastic cylinder with wires.
3. Measure the resistance with a multimeter. At room temperature it should be 4–7 kOhm.
4. Place the sensor in ice for 10 minutes - the resistance should increase to 20–30 kOhm.

If the resistance does not change, the sensor is faulty and requires replacement. In refrigerators Bosch older than 2018, the sensors are often unified, but it is better to buy original ones (the article numbers are indicated in the documentation).

4. Freon leak or clogged capillary tube

If the refrigerator Bosch works without stoppingbut does not freeze, and the condenser (grid on the back wall) remains cold, this is a sign freon leaks or a blockage in the system. In models with NoFrost leakage often occurs in places where the evaporator tubes are soldered, and in conventional refrigerators - due to corrosion of the circuit.

Causes of leakage:

• 🔧 Mechanical damage to tubes during defrosting or transportation.
• 🕳️ Corrosion of aluminum tubes (typical for refrigerators over 10 years old).
• 🔥 Overheating of the compressor due to a faulty condenser fan.

How to confirm a leak:

• Touch the condenser (grid at the back) - if it is room temperaturethere is no freon.
• Shine a flashlight on the evaporator tubes - look for oily ones spots (a sign of microcracks).
• Listen to the compressor: when there is a leak, it works louder, but without the characteristic "gurgling" of freon.

⚠️ Attention: It is impossible to fix a freon leak on your own - you need a specialist with evacuation and charging equipment. In refrigerators Bosch with refrigerant R600a (isobutane), leakage is dangerous - the gas is explosive at high concentrations. Do not turn on the refrigerator until repaired!

What happens if you ignore a freon leak?

If the leak is not eliminated, the compressor will wear out, which will lead to its breakdown (the cost of replacement is up to 70% of the price of a new refrigerator). In addition, in systems with R600a there is a risk of fire when contacts spark.

5. Malfunction of the compressor or start relay

The compressor is the “heart” of the refrigerator. If it does not create the required pressure, the freon does not circulate and the freezer does not cool. In refrigerators Bosch compressors Embraco or Secop are considered reliable, but can wear out over time. Also, the problem may lie in start relay —it is responsible for starting the engine.

Signs of a compressor malfunction:

• 🔊 The compressor hums, but does not start (relay clicks are heard).
• 🔥 The compressor housing is too hot (above +90°C).
• ⚡ An error appears on the display E1 or F1.

How to check:

1. Turn off the refrigerator and touch the compressor (black cylinder at the back). If it scalding hot is a sign of an interturn short circuit.
2. Remove the starting relay (box on the compressor) and check it with a multimeter:

   Normal resistance windings:
   - Operating: 15–30 Ohm
   - Starting: 30–50 Ohm

3. If the resistance is absent or too high, the compressor is faulty.

In models Bosch Serie 8 with inverter compressors, diagnostics are more difficult - specialized equipment is required. Independent repair of the compressor is impossible - it is completely changed. The cost of a new compressor for Bosch is from 8,000 to 15,000 rubles (depending on the model).

6. Problems with the control board

In refrigerators Bosch with electronic control (series Serie 6, Serie 8) it is responsible for the distribution of cold main board. If it fails, the compressor may work, but there is no signal to cool the freezer. Frequent causes of board failure:

• ⚡ Power surges in the network.
• 💧 Moisture ingress (for example, during defrosting).
• 🕰️ Natural wear of capacitors (through 7–10 years of operation).

Symptoms of board malfunction:

• 📛 All indicators are lit on the display or an error is displayed Err.
• 🔄 The refrigerator spontaneously reboots.
• ❄️ The freezer either works or turns off for no reason.

How to solve the problem:

1. Unplug the refrigerator for 10 minutes - sometimes this helps clear errors.
2. Check the fuse on the board (in models KGN39 it is located next to transformer).
3. Inspect the board for swollen capacitors or burnt tracks.

⚠️ Attention: Repairing the control board requires soldering skills and knowledge of circuit design. In 80% of cases, it is cheaper to replace the entire board (cost for Bosch Serie 6 - about 5,000–7,000 rubles). Before purchasing, check the part number of the board - it is indicated on the sticker.

7. Damage to the seal or door

If the sealing rubber on the freezer door is worn out or deformed warm air penetrates insideand the temperature does not drop to the desired level. In refrigerators Bosch with a system NoFrost this leads to icing of the evaporator and the fan stops.

How to check the seal:

• 📏 Close door and place a piece of paper between the seal and the body. If the sheet falls out, the seal is broken.
• 🔦 Inspect the elastic band for cracks or deformations (especially in the corners).
• 💧 Check if the seal is freezing - this is a sign of moisture penetration.

How to fix:

1. If the seal is dirty, wash it with warm water and soap and dry it.
2. If the rubber is deformed, try restoring its shape with a hairdryer (heat to +70°C and shape it with your hands).
3. If the seal is torn, replace it (original ones for Bosch cost from 1,500 rubles).

Also check door hinges - if they sag, the door will not fit tightly. In models Bosch KGE36 hinges are adjusted with a hex key.

FAQ: Frequently asked questions about Bosch refrigerators that do not freeze

My Bosch KGN39 refrigerator works, but the freezer does not freeze, but The refrigerator compartment is working normally. What's the matter?

Your model has two separate cooling systems: for the refrigerator and freezer compartments. If the refrigerator compartment works, but the freezer does not, the problem may be:

• Faulty freezer temperature sensor (you need to check with a multimeter).
• Clogged capillary tube in the freezer circuit.
• Freon leakage only in the freezer circuit (found in models with two compressors).

Start by defrosting for 12 hours - if that doesn’t help, call a technician for diagnostics.

The Bosch Serie 6 refrigerator shows error E2 and does not freeze. What to do?

Error E2 in refrigerators Bosch Serie 6 i Serie 8 means a problem with freezer temperature sensor. Try:

1. Disconnect the refrigerator from the mains for 5 minutes, then turn it on again.
2. If the error remains, replace the sensor (part number for KGN39 — 00646050).
3. Check the wiring from the sensor to the control board - it may have come loose contact.

If after replacing the sensor the error repeats, the problem is in the control board.

Is it possible to fill freon into a Bosch refrigerator yourself?

No. Charging freon requires:

• Special equipment (vacuum pump, pressure gauge) manifold).
• Knowledge about the types of refrigerants (R134a or R600a is used). Bosch R134a or R600a is used).
• Ability to solder copper-aluminum tubes.

Incorrect charging can damage the compressor or cause a leak. Contact the service center.

Why does the Bosch refrigerator not freeze after defrosting?

Possible reasons:

• In models NoFrost after defrosting, the fan may have iced up - repeated defrosting is required for 24 hours.
• During defrosting it could be damaged temperature sensor (check the resistance).
• If the refrigerator was turned off for a long time, oil in the compressor it could drain - wait 2-3 hours before turn on.

How much does it cost to repair a Bosch refrigerator if it does not freeze?

The cost depends on the reason:

Breakage	Repair cost (rub)
Replacement of temperature sensor	1 500–2 500
Repair of control board	3 000–6 000
Freon leakage + refilling	5 000–9 000
Replacement of compressor	8 000–15 000

Prices are indicated without the cost of spare parts. centers Bosch diagnosis is usually free.