The capillary tube is one of the key elements of the refrigeration circuit, which directly affects cooling efficiency. However, finding it in a modern refrigerator is not so easy: manufacturers hide the parts behind panels, thermal insulation and plastic casings. If you are faced with a malfunction (for example, clogged capillary or freon leak) or simply want to understand the device, this article will help you determine exactly where the capillary system passes in your model.
We will analyze the location of the capillary in refrigerators of different types: drip, No Frost and even rare ones absorption. You will learn how to visually distinguish a capillary tube from other elements (for example, from filter-drier or condenser), and also receive practical tips on accessing it without the risk of damaging the refrigeration circuit. For clarity, we present diagrams and photographs of real models (Atlant, Samsung, Indesit etc.).
What is a capillary tube and why is it needed
A capillary system is a thin copper or aluminum tube with a diameter 0.6–1.2 mmthat performs two critical functions:
- 🔹 Freon throttling: reduces pressure refrigerant in front of the evaporator, due to which it is cooled.
- 🔹 Flow adjustment: ensures a uniform supply of freon to the evaporator, preventing water hammer.
In contrast from thermostatic valve (TRV), which is installed in powerful industrial systems, the capillary tube is used in 90% of household refrigerators due to its simplicity and reliability. However, its small diameter makes the system vulnerable to clogging with oil particles, moisture or freon decomposition products this is one of the most common causes of breakdowns after 5–7 years of operation.
It is important to understand that the capillary works in tandem with filter-drier (usually a white cylinder next to the compressor). If the filter becomes clogged, the pressure in front of the capillary increases, which can lead to its rupture or freon leakage. Signs of malfunction:
- ❄️ The freezer works, but the refrigerator does not (or cools poorly).
- 🔥 The compressor works without stopping, but the temperature does not drop.
- 💧 On the back frost or ice appears on the refrigerator wall in atypical places.
Where is the capillary tube located: general diagram
The capillary system always connects three key components of the refrigeration circuit:
- Filter drier (installed at the outlet of the capacitor).
- Capillary tube (passes inside the rear wall or along its perimeter).
- Evaporator (located inside the chamber or behind the rear panel).
Typical arrangement using the example of a drip refrigerator:
- From the compressor, freon under high pressure enters condenser (grid on the back wall).
- After condenser, the gas turns into liquid and passes through filter-drier.
- Next, liquid freon enters capillary tubewhich leads to the evaporator (in the refrigerator or freezer).
In models No Frost the circuit becomes more complicated: the capillary can branch into several tubes (for example, for separate cooling of the refrigerating and freezing chambers). Also, in such refrigerators they often install bypass circuit (bypass) to defrost the evaporator.
How is the capillary different from other tubes in the refrigerator?
The capillary tube is thinner than the others (diameter ~0.8 mm versus 4–6 mm for mains) and usually has no insulation. It is easy to confuse it with:
- Drain tube (plastic, leads to the condensate tray).
- Tube thermostat (thin, but not metal, often corrugated).
- Return line (thick, goes from the evaporator back to the compressor).
How to find the capillary in different types of refrigerators
1. Drip refrigerators (with a “crying” evaporator)
In most models (Atlant, Biryusa, Stinol), the capillary tube passes:
- 🔧 Rear of the refrigerator: from the filter-drier (next to the compressor) up the back wall, then disappears under the thermal insulation.
- 🔍 Inside the chamber: comes out near the evaporator (usually behind the plastic panel on the back wall).
To gain access:
Disconnect the refrigerator from the mains and defrost it
Remove the lower back cover (secured with 2-4 screws)
Find the filter drier (white cylinder with copper tubes)
Trace the thin tube from the filter up - this is it capillary
To access the area inside the chamber, remove the internal evaporator panel-->
Attention! In refrigerators with a bottom freezer (for example, Samsung RB30J3000WW), the capillary may pass through on the side the body, and not from the back. In this case, access will require removing the side panel.
2. No Frost refrigerators
In systems No Frost (LG GA-B489YQZL, Bosch KGE39AW2AR) the capillary tube is often bifurcated:
- 🍃 One branch goes to main evaporator (hidden behind the back panel of the freezer).
- ❄️ The second - to additional evaporator fridge compartment (if the model is with Full No Frost).
Features:
- 🔧 The capillary can be hidden under polyurethane foam insulation —to access you will need to carefully cut off part of the insulation.
- 🔍 In some models (Liebert, Electrolux) the tube passes inside the fan box.
⚠️ Attention: In refrigerators No Frost with electronic control (for example, Samsung RL60) the capillary system can be equipped solenoid valve to switch the flow of freon. Do not confuse it with. thermostat!
3. Absorption refrigerators (gas)
In absorption models (Dometic, Electrolux EN3885) capillary the tube is replaced by throttle device, but the location principle is similar:
- 🔥 The tube goes from generator (heating element) to evaporator.
- 🔧 Often hidden inside sealed unit —access without disassembling the case is impossible.
How to visually identify capillary tube
In order not to confuse the capillary with other elements, pay attention to the following signs:
| Feature | Capillary tube | Other tubes |
|---|---|---|
| Diameter | 0.6–1.2 mm |
4–8 mm (main)2–3 mm (drainage) |
| Material | Copper or aluminum without insulation | Copper (with insulation), plastic (drainage) |
| Location | From the filter drier to the evaporator, often spiral curved for compensation length | Straight sections (mains), corrugated (thermostat) |
| Temperature | Cold throughout (with the compressor running) | Hot (discharge), warm (return) |
If in doubt, use heating test:
- Turn on the refrigerator for 10-15 minutes.
- Caution touch the tubes (don’t get burned!):
- 🔥 Hot —discharge from the compressor.
- ❄️ Cold —capillary or return line.
- 🌡️ Warm —return freon to the compressor.
Frequent problems with the capillary system and their symptoms
Most capillary malfunctions are associated with it clogging or mechanical damage. Let's consider typical symptoms:
1. Clogged capillary tube
Causes:
- 🛢️ Oil decomposition products (solid deposits form over time).
- 💧 Moisture in the system (freezes in the capillary, blocking the flow).
- 🔧 Metal shavings (entered during careless repairs).
Signs:
- ❌ The compressor is running continuously, but the refrigerator does not freeze.
- ❄️ The freezer is cold, the refrigerator is warm.
- 🔊 An outsider hissing sound in the circuit (freon is trying to pass through blockage).
2. Break or crack of the capillary
Occurs due to:
- 🔨 Mechanical damage (for example, when moving the refrigerator).
- 🧊 Corrosion (at places of contact with moisture).
- 🔥 Overheating (if the capillary touches a hot compressor).
Signs:
- 💨 Refrigerator completely stops cooling through 1–2 days.
- 🛠️ On the back wall you can see oil stains (freon + oil leak).
- 🔇 The compressor turns on, but turns off quickly (protection is activated).
⚠️ Attention: If you detect a freon leak (by smell or oil traces), do not turn on the refrigerator - this can lead to failure compressor! Immediately turn off the power and call a technician.
Is it possible to clean or replace the capillary yourself
Theoretically, cleaning the capillary tube is possible, but in practice this a risky procedurewhich requires:
- 🛠️ Special equipment: a vacuum pump, a manometric manifold, a cylinder with freon.
- 🔧 Work experience with a refrigeration circuit (soldering error can lead to leakage).
- 🧪 Knowledge of freon types (in old models -
R12, in new ones -R134aorR600a).
If you still decide to try, here is a short algorithm:
Pump out the freon from the system using a vacuum pump
Unsolder the capillary from the filter drier and evaporator
Purge the tube with nitrogen under a pressure of 10–15 bar
If the blockage does not clear, replace the capillary with a new one
Solder the circuit, vacuum and fill with freon -->
Real risks of self-repair:
- 💥 Damage to the circuit in case of careless soldering.
- 🔥 Fire when working with an open flame (freon is flammable!).
- 🚫 Loss of warranty (if the refrigerator is under warranty, self-repair will void it).
Photos and diagrams of the location of the capillary in popular models
Below are real diagrams and photographs indicating the location of the capillary tube in refrigerators of different brands.
1. Atlant MHM 1705 (drip)
Capillary tube (marked red):
- 🔹 Passes along the back wall to the right.
- 🔹 Enters the evaporator of the refrigerator compartment through the hole in the upper part.
2. Samsung RL-34 EBMG (No Frost)
Features:
- 🔹 Capillary bifurcated: one branch goes to the freezer, the second to the refrigerator.
- 🔹 The tube is hidden under plastic fan box.
3. Indesit DF 4180 (two-chamber)
Capillary system:
- 🔹 Passes on the left side rear wall.
- 🔹 Has two loops to compensate for temperature expansion.
⚠️ Attention: There may be inaccuracies in the diagram - manufacturers periodically change the layout. Always check with real arrangement of tubes in your model!
FAQ: Frequently asked questions about the capillary system
Is it possible to clean the capillary tube without soldering?
No. The capillary is sealed on both sides (to the filter-drier and evaporator), so to clean it it is necessary unsolderAlternative methods (blowing with air, flushing with solvents) are ineffective and can damage the system.
How understand that it is the capillary that is clogged, and not the filter drier?
If it is clogged, the compressor will overheat, and the condenser will remain cold. If it is clogged, the condenser heats up, but the evaporator does not cool. by measuring the pressure in different parts of the circuit. filter, the compressor will overheat and the condenser will remain cold. If clogged capillary, the condenser heats up, but the evaporator does not cool. Accurate diagnostics can only be carried out with a pressure gauge, measuring the pressure in different parts of the circuit.
What to do if the capillary tube bursts?
If the capillary breaks, it is required complete replacement of the tube followed by refilling freon. Self-repair is not recommended - vacuum soldering is required. Cost of work at a service center: from 3,500 to 7,000 rubles (depending on the model).
Why is the capillary tube hot, but the refrigerator does not freeze?
This sign critical blockage or lack of freon. A hot tube means that the freon does not pass further (no cooling due to evaporation). Also check whether the compressor has burned out - this can give similar symptoms. starting capacitor compressor - this can give similar symptoms.
Is it possible to replace the capillary tube with a thicker one to avoid blockages?
No. The diameter of the capillary is designed for a specific one. type of freon i compressor performance. Increasing the diameter will lead to incorrect operation of the system: the compressor will operate in extreme mode, and the temperature in the chambers will become unstable.