Opening the refrigerator compressor: when it is necessary and how to do it correctly

Opening a refrigerator compressor is a task that is faced with serious breakdowns when conventional diagnostics do not produce results. This process requires not only technical skills, but also an understanding of the cooling system. The compressor (or motor-refrigerator) is the heart of the unit, and its disassembly may be necessary to change the oil, check the windings, eliminate mechanical damage, or clean up contamination.

However not every malfunction requires opening. Problems are often solved by replacing the relay, checking the capacitor, or refilling freon. Before disassembling, make sure that other diagnostic methods have been exhausted. In this article, we will analyze in what cases opening the compressor is justified, what tool is needed, and how to carry out the procedure without the risk of permanently damaging the refrigerator.

Important: if you do not have experience working with refrigeration equipment, it is better to entrust this task to professionals. Incorrect actions can lead to freon leakage, damage to the windings, or even an explosion of the sealed system due to residual pressure.

When do you really need to open the compressor?

Disassembling the compressor is a last resort. Here are the situations in which it may be justified:

• 🔧 Mechanical blockage — if the compressor hums but does not start, the piston group may be jammed. This often occurs due to wear of parts or metal shavings.
• 💡 Breakage or inter-turn short circuit of the windingswhich cannot be diagnosed with a multimeter without opening it. For example, if the resistance of the windings is normal, but the engine does not work.
• 🛢️ Replacement oil - if the compressor overheats or makes unusual sounds, the reason may be degraded oil (especially after 10+ years of operation).
• 🧲 Cleaning from metal dust - when bearings or pistons wear out, abrasive accumulates in the system, which accelerates failure.
• 🔄 Replacing valves - if the compressor does not create the required pressure, the problem may be worn inlet/exhaust valves.

On the other hand, there are cases when opening does not make sense:

• ❌ The compressor burned out (you will feel a characteristic burning smell) - it’s easier to replace the whole thing.
• ❌ Freon leakage due to cracks in the housing - the tightness after disassembly is almost impossible to restore.
• ❌ Refrigerator over 15 years old - repairs will cost more than a new compressor.

⚠️ Attention: If the refrigerator is still under warranty, opening the compressor will void it. Manufacturers (for example, Atlant, Indesit, Samsung) consider this to be unauthorized intervention.

Preparation: tools and safety precautions

Before starting work, collect everything you need. Without the right tool, the risk of damaging the compressor or getting injured increases significantly.

Required tool

Also prepare the workplace:

• 🪛 Work in good conditions in a ventilated area - freon is toxic.
• 🧹 Cover the floor with cardboard or film - oil from the compressor may leak.
• 🔌 Disconnect the refrigerator from the network 12 hours before starting work - this will allow the freon to condense.

⚠️ Attention: If The refrigerator uses freon R600a (isobutane), it is extremely explosive! Even a spark from static electricity can cause a fire. Work away from open flames and sources of sparks.

Disconnected the refrigerator from the network for 12+ hours|

Prepared a fire extinguisher (for freon R600a)|

Checked the integrity of the vacuum hoses pump|

Put on safety glasses and gloves|

Took the refrigerator outside or into the garage-->

Step-by-step instructions: how to open the compressor

The process of disassembling the compressor can be divided into 4 stage: disconnection from the system, opening the case, diagnostics of internal parts i reassembly. Let's look at each in detail.

Stage 1: Disconnecting the compressor from the refrigeration unit system

Before removing the compressor, you need to bleed off the freon and unsolder the tubes:

1. Connect the vacuum pump to the service port (usually located on the filter drier). Pump out the freon into a cylinder (if you plan to reuse it) or vent it in a well-ventilated area.

2. Use a pipe cutter, carefully cut off the filling and suction tubes at a distance of 10–15 cm from the compressor. Do not saw with a grinder —metal dust will get inside the system.

3. Heat the soldering areas with a torch and remove the remaining pipes from the compressor pipes. Be careful - oil under pressure may remain inside!

Step 2: Disassembling the compressor housing

Now you need to get to the internal parts:

1. Remove the start relay (usually secured with latches or screws). Check it for melting or burnt contacts.

2. Turn the compressor upside down (pipes down) and clamp it in a vice. This will prevent oil from leaking out.

3. Using a hacksaw, carefully cut off the upper part of the body along the weld seam. Do not cut too deeply - there are windings and a piston group inside!

4. After the cut, pry up the cover with a screwdriver and remove it. Be prepared for the fact that oil may splash out from under it.

What to do if the lid cannot be removed?

If the lid is “stuck” due to old oil, try slightly heating the case with a hair dryer (no higher than 100°C). Then gently tap the edge with a hammer through the wood spacer. Do not apply excessive force - you can damage the windings.

Stage 3: Diagnostics of internal parts

After opening, inspect:

• 🔩 Piston group for chips, scuffs or ring wear.
• 🧲 Valves —they should fit tightly, without cracks.
• 🛢️ Oil —if it is black or with metal particles, replacement is required.
• 🔧 Bearings —check the play shaft.

To check the windings:

1. Disconnect the terminals from the windings.
2. Measure the resistance between the terminals:
   • Between C (common) and S (start) —should be ~20–30 Ohm.
   • Between C and R (working) — ~10–15 Ohm.
   • Between S and R —the sum of the two previous values (~30–45 Ohm).

If the resistance is 0 or ∞ - open circuit or short circuit.

Typical mistakes and how to avoid them

Even experienced craftsmen sometimes make mistakes when opening the compressor. Here are the most common of them and ways to prevent them:

Another common problem is incorrect assembly. For example, if the welding seam is not aligned when installing the cover, the compressor will lose its seal. To avoid this:

• 📏 Before welding, mark with a marker the position of the cover relative to the body.
• 🔥 Use argon welding for sealing - it gives a stronger seam than soldering.
• 🧪 After assembly, check the tightness with a soap solution (there should be no bubbles).

⚠️ Attention: If you have changed the oil, be sure to vacuum the system before charging freon! Remaining air and moisture lead to corrosion and deterioration of heat transfer.

How to check a compressor after repair

After assembling and installing the compressor back, you need to make sure that it is working correctly. Here is a step-by-step verification algorithm:

1. Visual inspection:

   • Check the integrity of the weld.
   • Make sure that the tubes are not pinched and do not touch the body.

2. Checking the winding resistance (repeat the measurements with a multimeter). The values must coincide with those before the repair.

3. Leakage test:

   • Connect the compressor to a nitrogen cylinder (pressure ~10 atm).
   • Apply a soap solution on all connections - bubbles will indicate a leak.

Test run:

• Connect the compressor to the network via the start relay.
• It should start without extraneous sounds (knocking, grinding).
• After After 10–15 minutes of operation, the case should be warm, but not hot.

If the compressor does not start:

• 🔌 Check the voltage in the network (should be 220–230 V).
• 🔧 Make sure the relay is working properly (no contacts burnt).
• 🧲 Check the windings for a short circuit.

If the compressor starts but does not create pressure:

• 🛢️ Possible freon leak - check the system for leaks.
• 🔩 Wear of valves - repeated disassembly will be required.

When is it better to replace a compressor rather than repair

Repairing a compressor is not always justified. Here are the cases when it is cheaper and more reliable to install a new one:

• 💸 The cost of repairs exceeds 60% of the price of a new compressor (for example, for Beko or Liebherr a new motor costs ~8-12 thousand rubles).
• 🔥 Compressor burnt out (you will smell a burning smell, the windings have turned black).
• 🕳️ There is a crack or corrosion in the housing that breaks the seal.
• ⏳ The refrigerator is more than 15 years old - a new compressor may not pay for itself.
• 🔄 Repair has already been carried out previously, but the problem repeats.

When choosing a new compressor, pay attention to:

• 🔹 Freon type — must match the original (for example, R134a or R600a).
• 🔹 Power —must be no lower original (indicated on the nameplate of the old compressor).
• 🔹 Oil type —for R600a polyester oil is used, for R134a —mineral.
• 🔹 Location of pipes —they must coincide on the side and angle.

Average cost of a new compressor for popular models:

Refrigerator brand	Compressor model	Cost, rub.
Atlant	Danfoss NL6L	7 500 – 9 000
Indesit	Embraco EGX 90H	8 000 – 10 000
Samsung	Secop (Danfoss) SC15G	10 000 – 12 000
LG	LG Inverter Linear	15 000 – 20 000

⚠️ Attention: Prices for compressors may vary depending on the region and exchange rate. Check current offers with official dealers or service centers.

Alternative diagnostic methods without opening

Before disassembling the compressor, try alternative diagnostic methods. They will help save time and avoid risks.

1. Check with a multimeter

Remove the starting relay and test the windings:

• 🔌 Resistance between terminals:
  • C-S: starting winding (~20–30 Ohm).
  • C-R: working winding (~10–15 Ohm).
  • S-R: sum of two windings (~30–45 Ohm).
• 🔋 Checking for breakdown: resistance between any terminal and the housing must be ∞ (infinity). If there is a value, there is a breakdown to the housing.

2. Checking the current consumption

Connect the compressor through the current clamp:

• 📊 Normal starting current - 1.5–2.5 A (depending on the model).
• 📉 If the current is above 3 A, an interturn breakdown is possible.
• 📈 If the current is below 1 A, the winding is broken.

3. Checking the pressure

Connect the pressure manifold to the service port:

• 🔹 Suction pressure (low): ~0.5–1 atm.
• 🔹 Discharge pressure (high): ~10–15 atm.
• 🔹 If the discharge pressure is below 5 atm, the valves or piston group are worn out.

If these tests did not reveal problems, but the compressor still does not work normally, only then does it make sense to open it.

FAQ: Frequently asked questions about opening the compressor

Is it possible to open the compressor without unsoldering the tubes?

Technically it is possible, but this is extremely risky. depressurization of the housing when the cover is cut off. In addition, without unsoldering the tubes it is impossible to check the compressor for leaks after repair. If you still decide to take a risk, first bleed the freon through the service port and drain the oil.

What kind of oil should you fill in after opening?

The type of oil depends on the freon used:

• R134a, R404a —mineral oil (for example, Mobil EAL Arctic 32).
• R600a (isobutane)—polyester oil (for example, Emkarate RL 32H).
• R290 (propane)—also polyester, but with increased thermal stability.

The oil volume is usually indicated on the compressor nameplate (for example, 250–350 ml). After refueling, be sure to vacuum the system!

What to do if the compressor knocks after assembly?

A knock in the compressor after repair may indicate:

• 🔩 Deficiency oil —add to normal.
• 🔧 Wear of the piston group - you will need to replace the rings or piston.
• 🧲 Air getting into the system -vacuum and refill the freon.
• 🛠️ Incorrect assembly -check that they are not touching are the parts interconnected.

If the knocking sound is metallic and loud, most likely, piston blocking the compressor will have to be disassembled again.

How much does it cost to repair a compressor at the service?

The cost depends on the complexity of the work:

• 🔧 Diagnostics — 1,000–2,000 rubles.
• 🛠️ Oil change + cleaning — 3,000–5 000 rub.
• 🔄 Repair of piston group — 5,000–8,000 rub.
• 🆕 Replacement of the compressor — 8,000–15,000 rub. freon).

Some services offer free diagnosticsif you agree to repairs from them, check the conditions in advance.

Can I use it? compressor from another refrigerator?

Theoretically, it is possible, but several factors must be taken into account:

• 🔹 Freon type —must match (for example, R134a incompatible with R600a).
• 🔹 Power —the new compressor must have a similar or greater cooling capacity.
• 🔹 Location of pipes —if they do not match, the tubes will need to be re-soldered.
• 🔹 Type oil —when replacing freon, the oil also needs to be replaced.

It is best to select a compressor according to the model of the refrigerator (for example, through catalogs Danfoss or Embraco).