Repairing a refrigerator evaporator: how to seal a freon leak at home

The evaporator is the “heart” of the refrigeration system, where the refrigerant (freon) boils, absorbing heat from the chamber. If a crack or fistula forms in it, freon leaks, the compressor runs idle, and the food spoils. Craftsmen charge from 3,000 to 8,000 rubles for soldering work, but if you have the tools and are careful you can solder the evaporator yourself.

This article contains detailed instructions with photos of the stages, the choice of solder for copper and aluminum, as well as common mistakesdue to which the soldering does not hold. We will look at how to determine the location of the leak, prepare the surface and check the tightness after repair. If your refrigerator (Indesit, Samsung, Atlant or another brand) has stopped freezing, but the compressor is humming, most likely the problem is in the evaporator.

Signs of a malfunctioning evaporator: how to confirm a freon leak

Before you take it for a soldering iron, make sure that the problem is in the evaporator. Here are the key symptoms:

• 🔊 The compressor works without stopping, but the refrigerator is not cooling. This is the main sign of a refrigerant leak.
• ❄️ On the back wall of the chamber no frost (in models with a drip system) or it forms only in one corner.
• 🌡️ The temperature in the chamber is above +10°C, despite the maximum cooling settings.
• 💨 The air coming out of the ventilation grilles not cold (relevant for systems No Frost).

If at least 2-3 signs match, the probability of a freon leak is 90%. To accurately localize the problem, inspect the evaporator for oil stains (freon comes out along with the oil from the compressor) or green oxides on the copper. The evaporator is hidden behind the back panel of the freezer. chambers, in conventional models - behind a plastic cover on the back wall. refrigerators with the No Frost system the evaporator is hidden behind the rear panel of the freezer; in conventional models, behind a plastic cover on the rear wall.

⚠️ Attention: Do not confuse freon leak with clogged capillary tube! When clogged, the compressor also heats up, but there will be uniform ice on the evaporator, and not local freezing.

Tools and materials: what you need to solder the evaporator

For high-quality repairs you will need a specialized tool Do not try to get by. a household soldering iron - it does not heat the metal to the required temperature. Here is the full list:

If the evaporator is aluminum (found in budget models Beko or Pozytron), you will need special solder for aluminum (for example, Castolin 190) and flux F-SW21. Soldering aluminum is more difficult due to rapid oxidation - experience is required.

Determine the evaporator material (copper/aluminium)

Buy solder and flux for a specific metal

Prepare gas burner and testing equipment

Disconnect the refrigerator from the network and defrost

Drain the remaining freon (if you have access to the service port)-->

Step-by-step instructions: how to solder the refrigerator evaporator

Process soldering requires care. Errors at this stage will lead to repeated leakage or damage to the evaporator. Follow the algorithm:

1. Removing the evaporator

Disconnect the refrigerator, defrost and remove the back panel. No Frost you will have to remove the fan and air ducts. The evaporator is usually attached to rivets or screws - they need to be carefully drilled or unscrewed.

If the freon has not yet leaked completely, do not cut off the tubes - first bleed the gas through the service port (it is located on compressor). For this you will need gauge manifold and a hose. Open the valve for 10-15 seconds until the pressure drops to zero.

2. Cleaning and preparing the surface. data-i="127">Clean the soldering area

Clean the soldering area emery. paper (grain 120–240). data-i="134">apply a patch or with a metal brush until shiny. Remove all oxides - they will interfere with the adhesion of the solder. Then apply flux with a brush (it should cover the area 1-2 cm wider than the crack).

For copper, use borax-based flux; for aluminum, use special active compounds. If the crack is large (more than 2 mm), you can patch made of copper foil 0.3–0.5 mm thick.

3. Soldering the evaporator

Turn on the burner and heat the soldering area to dark red color (for copper ~400°C) bring the solder - it should melt from the heat of the metal, not the flame. soldering iron along the crack, evenly distributing the solder. For reliability, make 2-3 layers.

When soldering aluminum, use argon environment (if possible) - this will prevent oxidation Without argon. the soldering will be less durable.

What to do if the solder does not stick?

If the solder rolls off or does not hold, the problem is insufficient heating or poor stripping Try:

1. burners.

2. Clean the surface again and apply flux.

3. Use a more active flux (for example, F-34A for difficult cases).

4. Checking the tightness

After soldering, cool the evaporator and check the seam for tightness. To do this:

1. Connect to the service port a pressure gauge.
2. Pump into the system nitrogen under pressure 10–15 atm.
3. Apply to the seam soap solution - if bubbles appear, there is a leak.

If the test is passed, you can start filling freon. If not, repeat soldering.

Refilling freon after soldering: step-by-step algorithm

After successful soldering, the system is needed vacuum and fill with refrigerant. To do this you will need:

• 🔧 Vacuum pump (can be rented).
• 🧪 Cylinder with freon (type depends on the refrigerator model, usually R-134a or R-600a).
• ⚖️ Scales for freon dosage.

Connect the vacuum pump to the service port and pump out the air for 15–20 minutes. Then close the valve and watch the pressure gauge - if the pressure does not rise, the system is sealed. Now you can refill freon:

1. Connect the freon cylinder through the manifold.
2. Open the valve and watch the scales - refill exact dose (indicated on the nameplate compressor).
3. After refueling, turn on the refrigerator and check the temperature in the chamber after 2-3 hours.

⚠️ Attention: Do not fill freon “by eye”! Excess refrigerant is just as harmful as its lack - this will lead to compressor overload and repeated breakdown.

Common mistakes when soldering the evaporator and how to avoid them

Even experienced professionals sometimes make mistakes that ruin all their efforts. Here are the most critical ones:

• 🔥 Overheating of the metal — leads to deformation of the evaporator. Keep the burner at a distance of 3–5 cm and do not hold the flame in one place for more than 10 seconds.
• 🧴 Lack of flux —oxides remain on the surface and the solder does not stick. Apply flux generously, but not in excess.
• 🔧 Use of unsuitable solder for example, tin-lead solder for copper will quickly deteriorate. Use only copper-phosphorus or silver solders.
• 💨 Refilling freon without evacuation -moisture in the system will lead to clogging of the capillary tube after 1-2 months.

Another typical mistake is ignoring the leak test. Even a small microcrack will eventually cause a new leak. Always test the seam with nitrogen or a soap solution!

When soldering the evaporator is impractical: alternative solutions

Repairing the evaporator is not always justified. Here are cases when it is better to consider other options:

• 🕰️ Refrigerator more than 10 years - repair costs may exceed the cost of a new unit.
• 🔄 Evaporator damaged in several places —the soldering of each fistula weakens the metal.
• 🔧 The crack is located on the bend of the tube —here the metal is thinner, and the soldering will not last long.
• 💰 The cost of solder and freon exceeds 30% of the price of the refrigerator.

Alternatives:

• 🔄 Replacement of the evaporator - new copper evaporator for popular models (Atlant, Samsung) costs 2,500–4,000 rubles.
• 🆕 Purchasing a used refrigerator —on Avito or in thrift stores you can find working copies for 5,000–10,000 rubles.
• ♻️ Disposal with compensation - some stores (Eldorado, M.Video) give a discount on a new refrigerator when returning the old one.

⚠️ Attention: In refrigerators with with the No Frost system the evaporator is often integrated with the radiator. Replacing it requires complete disassembly of the freezer and is more expensive than conventional repairs.

FAQ: Frequently asked questions about soldering the evaporator

Is it possible to solder the evaporator with a regular soldering iron?

No. A household soldering iron (power up to 100 W) does not heat the metal to the required temperature. For soldering copper or aluminum it is required gas burner with a flame temperature of at least 1,000°C. The exception is small cracks on thin-walled tubes (up to 1 mm), but even here the risk of repeated leakage is high.

What kind of freon is needed for my refrigerator?

The type of freon is indicated on compressor nameplate (metal plate on the back wall). The most common:

• R-134a - modern models (LG, Samsung).
• R-600a (isobutane) - environmentally friendly, used in Atlant, Indesit.
• R-12 - outdated, found in Soviet refrigerators.

You cannot mix freons!

How much freon should be charged?

The amount of freon is indicated on the compressor nameplate (grams). For example, for Atlant MXM-180 it is 60–80 g R-600a. An excess of freon is just as harmful as a shortage - the compressor will work with overload. For an accurate dosage, use scales with an accuracy of 1 gram.

What to do if the refrigerator does not turn on after soldering?

Possible reasons:

1. Short circuit in the electrical circuit —check the fuse and thermostat.
2. Clogged capillary tube —nitrogen purge is required.
3. Compressor malfunction —if it hums but does not start, the winding may have burned out.

Start by checking starter relay (black box on the compressor).

Is it possible to solder an aluminum evaporator at home?

Technically yes, but it is difficult due to the rapid oxidation of aluminum. You will need:

• Special solder (Castolin 190, AluFlux).
• Active flux (F-SW21).
• Argon environment (optional, but desirable).

Without experience, it is better to entrust this work to a master - incorrect soldering will lead to a second leak in 1-2 months.