Can I test the refrigerator start relay myself?

Yes — the shake test is a quick DIY check. Unplug the fridge, pull the relay off the compressor (it's on the back of the compressor, usually accessible from behind or underneath the fridge). Shake the relay near your ear. If you hear rattling inside, the relay has failed and needs replacement. A working relay is silent when shaken.

Refrigerator Compressor Not Working? Signs, Causes & Repair Costs (2026)

Q: What is a refrigerator start relay and how much does it cost to replace?

The start relay is a small electrical component (about the size of a matchbox) that plugs into the compressor and gives it the electrical kick it needs to start. When the relay fails, the compressor cannot start. You may hear a click every few minutes as the fridge tries to restart. A replacement start relay costs $15–$40 in parts, and a technician can swap it in under an hour for a total repair cost of $80–$150.

If your refrigerator compressor is not working, the most important thing to determine first is whether the problem is a failed start relay (a $30 part, easy to replace) or a genuinely dead compressor ($400–$700 to replace). Both cause the same symptom — a warm fridge — but the repair costs are completely different. This guide walks you through how to tell them apart.

Signs Your Compressor Is Not Working

Fridge and freezer both warm: Not just slightly warm — room temperature.
Clicking every 2–5 minutes: Classic start relay failure symptom.
Compressor extremely hot: Normal to be warm, abnormal to be hot enough to be painful to touch.
Motor runs constantly but no cooling: May indicate a refrigerant leak.
Complete silence from compressor: Relay or overload protector has cut power.

How the Compressor System Works

The compressor is the heart of your refrigerator's cooling system. It compresses refrigerant gas, raising its pressure and temperature. The hot compressed gas flows through the condenser coils (usually at the back or bottom of the fridge), releases heat, and cools into a liquid. That liquid then expands through an expansion valve into the evaporator coils inside the fridge, absorbing heat from your food and air — which is what creates the cold temperatures you feel when you open the door.

When the compressor doesn't run, the entire cooling cycle stops. Both the fridge and freezer sections will warm to room temperature within 4–6 hours.

Key components that can cause compressor failure symptoms:

Start relay: Provides the initial electrical boost to start the compressor motor.
Overload protector: Safety device that shuts off power to the compressor if it overheats.
Start capacitor: On some models, stores charge to help the compressor start.
Compressor motor: The actual mechanical pump — fails from age, refrigerant loss, or electrical damage.

The Clicking Sound: Start Relay Failure

The most common compressor-related complaint we hear is a clicking sound every 2–5 minutes, combined with a warm fridge. This is almost always a failed start relay — and it's the best-case scenario when diagnosing a compressor problem.

Here's what's happening: the fridge senses the interior is too warm and signals the compressor to start. The compressor tries to start, but the faulty relay can't provide the right startup voltage. The compressor's thermal overload protector trips (a safety mechanism that protects the motor from overheating). After 2–5 minutes, the overload resets and tries again. Click. And again. Click.

The Shake Test — Diagnose a Failed Start Relay in 60 Seconds

Unplug the refrigerator.
Pull the fridge away from the wall and locate the compressor at the back bottom — it's the large black cylinder.
The start relay is a small component (matchbox-sized) plugged into the side of the compressor. It usually has one or two wires.
Pull the relay straight off the compressor terminals.
Shake it near your ear. A rattling sound inside = relay has failed. A healthy relay is silent when shaken.
Purchase a replacement relay for your fridge model (check the model number inside the door) and plug it in.

Cost comparison: A replacement start relay costs $15–$40 depending on the brand. With labour, total repair cost is $80–$150. Compare this to a compressor replacement at $400–$700. Always test the relay first.

Overload Protector Failure

The overload protector is a thermal safety device that monitors compressor temperature and current draw. If the compressor overheats or draws too much current, the overload trips and cuts power — protecting the compressor motor from burning out. The overload protector can fail in the open (tripped) position, meaning it permanently cuts power to the compressor even when temperatures are normal.

Signs of a failed overload protector are similar to a relay failure: the compressor doesn't run, the fridge is warm, and there may be an occasional click. A technician can test the overload protector with a multimeter for continuity in under 10 minutes.

True Compressor Failure: Signs & Diagnosis

If the start relay and overload protector both test as functional, and the compressor still won't run — or runs but produces no cooling — the compressor itself has likely failed. True compressor failure is relatively rare in fridges under 10 years old, but it does happen — particularly in certain brands.

Signs the Compressor Itself Has Failed

Relay and overload protector are both new or test as good, but the fridge still doesn't cool.
Compressor hums or buzzes but produces no cooling (motor runs but isn't pumping refrigerant).
Technician measures very low or zero refrigerant pressure in the system.
Compressor body is extremely hot — not just warm, but painfully hot to touch — even at rest.

Samsung & LG Linear Compressors — A Note

Samsung and LG introduced linear compressors in their newer refrigerator lines. These compressors are more energy-efficient but have been associated with higher failure rates in some model years. Both companies extended warranties on affected models. If you have a Samsung or LG fridge from 2014–2019 that's no longer cooling, check whether your model number is covered under an extended warranty before paying for repairs.

Component	Average Parts Cost	Total Repair Cost (Parts + Labour)
Start relay	$15–$40	$80–$150
Overload protector	$20–$50	$90–$160
Start capacitor	$15–$35	$80–$140
Compressor replacement	$200–$500	$400–$700
Samsung/LG linear compressor	$300–$600	$600–$1,000+
Refrigerant recharge (if leak)	$80–$150	$150–$300

Repair vs Replace: The 50% Rule

Before authorizing a compressor repair, consider the age and value of your fridge. A useful guide is the 50% rule: if the repair cost exceeds 50% of what the fridge would cost to replace today, replacement is typically the better financial decision.

10-year-old fridge worth $600 replacement: A $500 compressor repair is not economical.
4-year-old premium fridge worth $2,500 replacement: A $650 compressor repair is economical.
Relay replacement at $120 on any age fridge: Almost always worth doing.

Our certified technicians will always give you an honest assessment of repair vs replacement before proceeding. We diagnose the root cause first — and if the compressor relay is the issue, we'll often have the part on the truck.

Frequently Asked Questions

The key signs are: the fridge and freezer are both warm despite the motor running, you hear a clicking sound every few minutes (the compressor trying and failing to start), the compressor body is extremely hot to the touch, and there is no cooling at all. If only the fridge section is warm but the freezer is fine, the compressor is likely working and the problem is a damper or fan.

The start relay is a small electrical component that plugs into the compressor and gives it the electrical kick it needs to start. When the relay fails, the compressor cannot start. You may hear a click every few minutes as the fridge tries to restart. A replacement start relay costs $15–$40 in parts, and a technician can swap it in under an hour for a total repair cost of $80–$150.

Yes — the shake test is a quick DIY check. Unplug the fridge, pull the relay off the compressor (at the back bottom of the fridge). Shake the relay near your ear. If you hear rattling inside, the relay has failed and needs replacement. A working relay is silent when shaken.

Compressor replacement typically costs $400–$700 for parts and labour, depending on the fridge brand and model. Premium brands like Sub-Zero, Viking, or newer Samsung linear compressors can cost $800–$1,200. At this price point, compare against the cost of a new refrigerator, especially if the fridge is over 8 years old.

Compressors fail from age (average lifespan 10–15 years), lack of maintenance causing overheating, electrical surges, refrigerant leaks that cause the compressor to run dry, or manufacturing defects (notably in some Samsung and LG linear compressor models). Keeping condenser coils clean extends compressor life significantly.

The 50% rule: if the repair cost exceeds 50% of the fridge's current replacement value, replacement is usually more economical. A compressor replacement at $500–$700 on a 12-year-old fridge worth $600 replacement value is not economical. On a 4-year-old premium fridge worth $2,000+, compressor repair at $600 makes perfect sense.

A clicking noise every 2–5 minutes is the classic symptom of a failed start relay. The fridge is trying to start the compressor, the relay fails to provide the right start voltage, the compressor thermal overload trips, the fridge waits, then tries again. This cycle repeats until the relay is replaced or the compressor overheats and stops trying entirely.