Refrigerator Compressor Replacement: A DIY Guide

The compressor is the heart of a refrigerator’s cooling system. It pumps refrigerant through the sealed system to remove heat from the interior and transfer it outdoors. When the compressor stops working properly, the refrigerator won’t stay cold enough to safely store food. Replacing a bad compressor is a complex but doable DIY project to revive an otherwise functional refrigerator. This guide provides everything you need to know to replace the compressor yourself.

Understanding Why the Compressor Failed

Before replacing the compressor, it helps to understand why it failed in the first place. Some of the most common reasons include:

• Faulty electrical components – Issues with starting components like relays, capacitors, and overload protectors can prevent the compressor motor from starting.
• Lubrication issues – Lack of oil causes increased friction and overheating. Oil leaks allow contaminants inside to damage internal parts.
• Refrigerant leaks – Low refrigerant due to leaks overworks the compressor and leads to premature wear out.
• Physical damage – External impacts can bend valves and crack internal seals. Debris sucked into the system can also cause damage.
• General wear and tear – Seals, bearings, and gaskets degrade over years of use, eventually failing.

While some causes, like an oil leak, may be repairable, most experts recommend replacing the whole compressor. Attempting to rebuild one with damaged internal components often leads to premature failure of the new replacement.

Refrigerator Compressor Types

There are three main compressor types used in household refrigerators:

• Reciprocating – Also called piston compressors. A motor-driven piston increases and decreases pressure inside a cylinder to move refrigerant. Common in mid-range models.
  • Pros: Energy efficient, moderate lifespan of 5-10 years
  • Cons: Noisier, more vibration prone, contains oil that must be managed during replacement
• Rotary – Uses rotating impellers instead of reciprocating pistons. Quieter and smoother operation. Often found in premium models.
  • Pros: Quiet, durable with 10-15 year lifespans, oil-less self-lubricating design
  • Cons: Less energy efficient, costs more to replace
• Linear – Modern compact design with a linear oscillating motor. Gaining popularity in contemporary kitchens.
  • Pros: Extremely quiet, 10-15 year lifespan, oil-less and uses environmentally friendly R600a refrigerant
  • Cons: Expensive to replace linear-specific components

Preparing for Compressor Replacement

Replacing a refrigerator compressor is an advanced DIY project requiring specialized tools, materials, and expertise working with refrigerants. Be sure you have everything needed for safe and proper technique:

Tools

• Refrigerant recovery machine
• Refrigerant gauges
• Vacuum pump capable of 500 microns of vacuum
• Amp meter
• Socket set
• Adjustable wrench
• Needle nose pliers
• Wire cutters/strippers
• Multimeter
• Tube cutter
• Brazing torch kit
• Nitrogen regulator with purge assembly

Materials

• Replacement compressor compatible with your refrigerator
• New filter drier appropriate for the oil type
• Refrigeration grade copper tubing if lines must be extended/replaced
• Silver alloy brazing rods
• R-600a or other propane refrigerant charging hose

Safety Gear

• Eye protection
• Work gloves
• Closed toe shoes
• Respirator mask for brazing

Other Essentials

• Shop rags
• Teflon tape
• Emery cloth
• Wire nuts
• Replacement overload and relay if needed

Before Starting

Completely empty and unplug the refrigerator. Taping compressors, pipe connections, etc, will reduce vibration and prevent accidental damage while handling the unit.

Step-by-Step Replacement Guide

Follow these steps closely to safely replace your refrigerator’s compressor. Attempting this with inadequate skills or preparation risks contaminating the sealed system and ruining the newly installed compressor. Consider hiring an HVAC technician unless you have prior experience.

Step 1 – Recover Refrigerant from the Sealed System

The existing charge must be properly recovered before any disassembly using an EPA-certified recovery machine:

1. Turn recovery machine on and allow pump to warm up for 10 minutes. Connect yellow hose with service valve depressor to suction port.
2. Locate and identify the major refrigerator components – compressor, condenser, evaporator. Trace the copper refrigerant lines connecting them.
3. Determine high and low pressure access ports. Typically labeled H and L.
4. Attach blue hose from recovery machine to liquid line’s high pressure port.
5. Fully open panel valves on both blue and yellow recovery machine hoses. Insert the compressor service valve depressor and hold 10 seconds to open.
6. Turn recovery machine on and allow it to automatically extract refrigerant until low pressure gauge near zero PSIG.
7. After extraction finishes, close hose panel valves and disconnect all hoses. Cap the access ports to keep moisture out. The existing compressor is now ready for removal.

Step 2 – Remove and Prepare the New Compressor

With refrigerant evacuated, the old compressor can be disconnected:

1. Label and disconnect any wiring to the compressor, including the start relay, overload protector, and power wires.
2. Cut away insulation on suction and discharge lines to access braze connections.
3. Heat joints with brazing torch until silver alloy melts. Remove tubes from compressor.
4. Unbolt the compressor from the base and lift out. Note orientation and location details for new unit.
5. Inspect inside cabinet for leaks, damage, or missing hardware. Repair if found.
6. Verify the new compressor model is identical to original. Transfer any brackets or hardware if needed.
7. Use emery cloth to polish the stubs of the remaining suction and discharge tubes for easier brazing.
8. Temporarily install compressor to check fit but leave disconnected for now.

Once alignment and compatibility verified, continue to next step.

Step 3 – Braze New Compressor Into Sealed System

With all joints cleaned and prepped, use silver alloy rods and nitrogen flow for brazing in the new compressor:

1. Align tube ends and orient new compressor into final position. Clamp lightly if needed to hold it in place.
2. Attach a nitrogen tank regulator with flow meter to compressor process stub to provide an inert gas purge during brazing.
3. Open nitrogen tank valve to pressurize line anywhere from 3-15 PSIG depending on refrigerant type originally used. This prevents oxidation while heating joints.
4. Use brazing torch to uniformly heat the joint between the new compressor tube stub and existing refrigerant line until rods melt and evenly flow into any gaps.
5. Repeat step #4 to braze the discharge line connection. Check for leaks and repairs before proceeding.
6. Once all joints are cooled and solid, close nitrogen tank valve and carefully release pressure from line.

The new compressor is now permanently joined into the sealed system.

Step 4 – Replace Filter Drier and Re-Evacuate System

Before recharging refrigerant, the system must be checked for leaks, evacuated, and fitted with a new liquid line filter drier:

1. Replace the filter drier by cutting into the liquid line and brazing in the new unit directed by the arrow for proper flow.
2. Connect vacuum pump with 500 micron capability to both low and high side access ports using service hoses.
3. Open gauges and pump suction valves. Allow vacuum pump to pull down to 500 microns and hold for 20 minutes minimum.
4. Close valves and observe vacuum gauge for another 20-30 minutes verifying microns stay below 800 in a stable hold after isolation. No leaks or contamination are present if vacuum holds.
5. If vacuum test fails, leak check and re-braze connections as needed until stable vacuum is achieved. System is now ready for refrigerant.

Step 5 – Recharge Refrigerant

With the system thoroughly leak checked and evacuated, correctly recharge refrigerant through the low side port:

1. Review the manufacturer’s service data plate or owner’s manual for the factory charge amount and refrigerant type. Charging adapters are often R-600a or R-134a.
2. Connect appropriate charging hose to refrigerant tank liquid port and system low side service port.
3. Set refrigerant tank upright and open both tank and low side manifold valves to begin adding refrigerant.
4. Weigh in the factory charge amount in ounces or grams. Brief freezing followed by rapid frost indicates undercharge. Overcharge causes coils to be too cold with low compressor amp draw.
5. Start refrigerator and make sure compressor is running and not tripping overload. Adjust charge if needed based on frost formation.
6. Disconnect gauges when properly charged and replace service port covers.

Monitor refrigerator temperature for proper cooling over the next 24 hours. The compressor should run smoothly with no abnormal noise or temperature fluctuation.

Conclusion

While replacing a burned out compressor requires specialized tools and HVAC technician level skills, this guide provides an overview of what’s required for a DIY refrigerator revival. Each step must be followed precisely to ensure contaminants are removed and the new compressor survives long term. Unless you have prior experience servicing sealed systems, consider hiring a professional for the evacuation, brazing, charging, and leak checking processes. Choose an identical replacement compressor to avoid major modifications. And never operate any system low on refrigerant – the compressor depends on it for lubrication and proper function.