A sudden stop of the compressor or a characteristic clicking sound, after which the refrigerator stops freezing, often indicates a failure of the start relay. This small but critical part is responsible for starting the engine and keeping it running normally throughout the cycle. Equipment owners Ariston often face the need to replace this component, since it is subject to constant electrical and thermal loads.
Replacing the relay yourself is a real opportunity to save on calling a technician if you have basic skills in handling tools. However, before proceeding with disassembly, you need to make sure that the problem lies precisely in this unit, and not in the compressor itself or the wiring. Incorrect diagnosis can lead to the purchase of unnecessary spare parts and loss of time.
In this article we will analyze in detail the symptoms of a malfunction, testing methods and the process of installing a new part on refrigerators Ariston. You will learn how to safely dismantle the old element and not damage the fragile evaporator tubes when accessing the unit.
Signs of a faulty start relay
The first and most obvious symptom is the failure of the compressor to start. You may hear the refrigerator hum for a couple of seconds, then there is a loud click and then there is silence. After some time, the cycle repeats. This indicates that starting relay cannot close the winding circuit or break it in time, which is why the thermal protection is triggered.
Sometimes the relay does not fail completely, but “burns out”. In such cases, the refrigerator may work, but intermittently: it turns on and off without reaching the desired temperature. It is also worth paying attention to the appearance of the part: if melting, blackening or a burning smell is visible on the housing, replacement is inevitable.
⚠️ Attention: If the compressor makes a dull hum when starting, but does not start, and the relay is new, the motor-compressor itself may be jammed. Attempts to turn it on multiple times can permanently damage it.
Another sign may be overheating of the relay housing. If, after a short operation, you touch the plastic box on the compressor and it burns your hand, it means that there has been a breakdown or a breakdown of the contact group inside. In normal mode, the relay may be warm, but not hot.
Necessary tools and preparation
To carry out repair work, you will need a minimum set of tools. First of all, you need pliers and a screwdriver (usually a Phillips or flathead screwdriver, depending on the model Ariston). Also, a multimeter for initial diagnostics will not be amiss, although replacement is often done by the “method of elimination.”
Be sure to prepare a clean rag and, possibly, a means for degreasing contacts if they have oxidized. Before starting any manipulations with the electrical part of the refrigerator, it is necessary to completely disconnect the unit from the power supply by unplugging the plug from the socket. This is a basic safety rule, which cannot be ignored.
☑️ Preparing for repairs
Give access to the back of the refrigerator. Make sure you have enough light to work with, as the compressor area is often obscured by housing or structural components. If there is a removable protective panel above the compressor, remove it.
Removing the old relay
The removal process begins with a visual inspection of the back wall of the refrigerator. The compressor is usually covered with a metal or plastic casing that must be removed. Fastenings can be with latches or screws. Carefully unscrew them or press out the latches, being careful not to drop the fasteners inside the housing.
On the compressor itself, in its lower part, you will see a black cylindrical or rectangular element - this is the starting relay. It is put on three pins coming out of the compressor housing. The relay can be additionally fixed with a metal bracket or a plastic clip.
Remove the fixing bracket, if any. Then gently pull the relay down. It should come off the pins. Do not apply excessive force to the sides to avoid breaking the plastic mounting ears or, worse, damaging the copper tubing leading to the compressor.
⚠️ Warning: The relay may be heavy due to the built-in thermal contact. When removing, hold it with your hand so that it does not fall and break the wires, which may be short.
After removing the relay, disconnect the wires. In some models Ariston the wires are inserted into the terminals on the relay body, in others the relay has a built-in block. Take a photo of the location of the wires before disconnecting so that when installing a new part you do not mix up the polarity.
Diagnostics and selection of a new part
Before buying a replacement, it is worth understanding why the old part burned out. Often the cause is a power surge or natural contact wear. If you plan to test the old relay with a multimeter, put the device in dial mode. The contacts must ring in a certain position (depending on the type: posistor or induction).
When choosing a new relay, the key parameters are the compressor power and the type of refrigerant, although visually they often differ in the shape of the housing and the number of contacts. There is always a marking on the relay body. For refrigerators Ariston it is important to choose an analogue with an identical terminal arrangement.
| Relay type | Principle of operation | Characteristic feature | Compatibility |
|---|---|---|---|
| Posistor (PTC) | Heating of the element and opening | Silence when cooling | Modern models |
| Induction | Electromagnetic retraction | Loud click | Old models |
| Thermal | Bimetallic plate | Overheat protection | Built in circuit |
| Combined | Combines functions | Complex circuit | Specific series |
Can a universal relay be used?
Universal relays (so-called “pills” or kits with adapters) are often suitable for many models, but their service life may be shorter than the original ones. They require careful selection of the adapter block to match the pins of your compressor. If possible, it is better to look for an original or a high-quality analogue for a specific compressor model indicated on the nameplate.
Pay attention to the coil voltage, if it is indicated. For household refrigerators this is usually 220V, but in some dual-compressor or industrial models there may be nuances. The markings on the compressor housing (for example, EMBRACO or DANFOSS) will help you find the exact compatibility table.
Installing a new relay on the compressor
Installation is carried out in the reverse order of dismantling. First, connect the wires to the terminals of the new relay. Make sure the connection is tight and secure. If the terminals are “loose”, they can be carefully tightened with pliers, but without fanaticism, so as not to split the plastic.
Place the relay on the pins of the compressor. It is important to observe the orientation here: on the body of the part there is often an arrow with the inscription UP or TOP. This side should face straight up. Incorrect orientation will result in the contacts not closing or the mechanism not working correctly.
⚠️ Attention: When placing the relay on the pins, do not put pressure on the compressor body itself or the copper tubes. The force should only be applied to the plastic housing of the relay. The tubes are very thin-walled and easily burst.
Secure the relay with a fixing bracket or clamp, if provided by the design. Make sure that the part fits tightly and does not wobble when slightly rocked. The vibration of a running compressor should not loosen the connection.
Checking the system functionality
After installing the new element and fixing all the wires, return the compressor protective casing to its place. Now you can turn on the refrigerator. In the first seconds, listen carefully: a characteristic startup sound should be heard, and the compressor will begin to vibrate and hum evenly.
Check the heating of the new relay during operation. After 15-20 minutes of operation, it may warm up slightly, but should not be hot. If the refrigerator began to get cold, and the on-off cycle became standard (for example, it works for 10 minutes, it stops for 20), then the repair was successful.
During the first 24 hours, observe the operation of the unit. If no problems arise, the replacement can be considered complete. Regularly check the cleanliness of the condenser at the back of the refrigerator, since dust is often an indirect cause of overheating and failure of electrical components.
Frequently asked questions (FAQ)
Is it possible to temporarily short-circuit the relay so that the refrigerator can be completed before purchasing a spare part?
Theoretically, start A compressor without a relay is possible by applying voltage directly to the working winding, but this is dangerous and not recommended. The compressor may burn out due to lack of protection against overheating and overload. In addition, without a starting winding, it can simply hum, but not spin, which will quickly lead to a wedge.
Why did the new relay burn out a week after replacement?
There may be several reasons: incorrect installation (inverted arrow UP), poor contact in the terminals, causing sparking, or, what’s worse is a malfunction of the compressor itself (an interturn short circuit), which “pulls” too much current.
Where can you find the relay markings on an Ariston refrigerator?
The markings are applied directly to the plastic body of the black relay hanging on the compressor. Also, information about the type of compressor and the required relay can be found on the nameplate sticker located inside the refrigerator compartment or on the back wall.
Is the relay different for refrigerators with No Frost and a drip system?
In principle, the relays are the same and depend on the type of compressor, and not on the defrosting system. However, in No Frost refrigerators the load may be higher due to more frequent switching cycles of fans and heating elements, so it is recommended to use only high-quality original components.