Why Does My Ice Maker Make a Knocking Sound?

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With random noises in your kitchen, you’re likely wondering, why does my ice maker make a knocking sound? You would be surprised at the number of sounds your household appliances make, especially when they’re suffering from a defect or temporary issue.

Ice machines are, by far, some of the noisiest devices on their own, let alone if they have a problem. With the right troubleshooting tips, you’ll have a clear understanding of why your ice maker might be making knocking sounds.

Normal Sounds Ice Makers Make

There are plenty of bits and pieces that go into making appliances as efficient as they are. From refrigeration coils to fans, you can bet that your ice maker will make plenty of noise.

Before we get into the specific reasons why your ice maker might be making knocking sounds, here are a few everyday noises you should expect to hear.

1. Fan Speed

Ice makers typically have fans that help to circulate cold air throughout the ice reservoir and ice chamber. This process not only makes freezing the ice cubes much faster but also helps to keep them frozen after they form.

You likely hear changes in fan speed depending on the internal temperature of the ice maker. For example, if the interior is too warm, the fan will speed up to cool it down, making a noise in the process.

2. Gurgling

If, at any point, it sounds like your appliance is making a gurgling or chugging sound, it could be the water moving from the reservoir to the freezing chamber. This sound may resemble the sound of water going down a drain, as the water travels into the lines.

Gurgling can also be attributed to the use of refrigerant. For the majority of the unit’s freezing power, it will rely on a refrigerant that needs to circulate continuously through the ice maker.

Gurgling may also be a sign that the refrigerant is being brought to the areas where it is required.

3. Loud Click

It’s the responsibility of your ice maker to maintain a specific temperature so that the stored ice doesn’t melt quickly.

You’ve likely noticed the appliance to make a gentle humming sound that eventually stops with a single loud click. This sound is probably the temperature control shutting off as soon as the internal temperature of the unit reaches freezing.

Alternatively, the loud click may also be a sign of the temperature control unit turning on if it’s too hot inside of the ice maker.

4. Buzzing or Sizzling

Sometimes, your ice maker is “smart” enough to know when it’s time to go through a defrost cycle, mainly if you invest in a more expensive machine. Buzzing and sizzling can relate to self-defrost modes being turned on.

If ice is forming in an essential part of the ice maker where it’s not supposed to be, your machine will automatically begin the defrosting process.

Why Does My Ice Maker Make a Knocking Sound?

It’s not guaranteed that if you hear your ice maker knocking that you’re going to be faced with a terrible issue that needs to be investigated. More often than not, homeowners find that knocking sounds are easily diagnosable and treatable without the help of a professional. However, this may not always be the case.

Below are the most common reasons as to why you might hear knocking sounds from your ice maker.

1. Vibration and Placement

Where you place your ice maker can have a lot to do with whether the machine makes noise or not. During installation, the instructions likely say to put the device on a stable and even surface.

When your ice maker begins its processes, it tends to vibrate, and if it’s unstable, it’s going to make a knocking sound. The knocking could be the appliance shifting on your counter or even banging against the wall.

The first step is to adjust your ice maker to make sure it is stable. If the knocking continues, it could be a different issue.

2. Compressor Operations

Portable ice makers typically have compressors, which are in a self-contained unit. At times, the compressor may be responsible for spreading cold air throughout the ice maker, depending on your model. When the compressor starts and stops, it’s likely to make a knocking sound.

If you’ve ever visited a hotel and have seen ice forming by their commercial machine, it will make a relatively loud knocking sound. Other commercial ice makers will have their cooling equipment located separately on the roof.

With your portable unit, the compressor is built-in, so it’s going to make a substantial amount of noise when the device is operating.

3. Heating

You might be wondering, why would an ice maker need heat to freeze water? The exciting aspect of these units is that they require freezing temperatures to make ice and heat to distribute the ice. The easiest way to explain the importance of heat is to understand how ice makers work.

After filling the water reservoir, the unit will bring water through the lines to the inner components of the machine where the ice molds can be found. When the water fills the cavities, finger prongs are then inserted and will begin to freeze the water.

Once the cubes are made, they stick to the finger prongs as they are brought back to the ice bucket. The way that your ice machine gets the cubes off of the finger prongs is by using heat, or sometimes air pressure, to shoot the ice off.

When the heating component is required, it may make a knocking sound similar to the compressor. However, if the knocking continues for more than a minute at a time, it’s likely not the heating.

4. Water Levels

Maintaining water levels is particularly difficult for homeowners with portable ice machines, as the device doesn’t have a water line attached at the back. Instead, you will be responsible for regularly refilling the machine.

At times, it can be easy to forget, and when your ice maker goes to make ice, it won’t have enough fluid to do so, resulting in knocking. This issue may also be prevalent in refrigerator ice makers, especially if the water line is clogged or improperly installed.

The knocking created from insufficient water levels is typically the machine trying to work but not having the fuel to do so. Always ensure you maintain healthy water levels for optimal ice production.

5. Cube Size

Most ice makers will come with a setting where you can change the size of the cubes it makes. Frequently you will be able to choose between small and large, though there may also be an option for medium cubes.

If your machine is poor in design, you may be selecting an ice size that is too large for it to handle. This process could result in cubes getting stuck rather than being passed through to the ice tray or basket.

Until the ice melts, the cubes could be causing parts to hold, which could result in a knocking sound. Typically, with this issue, the knocking will subside once you change the ice setting and opt for smaller cubes to be made.

6. Water Pump

Also known as a drain pump, the water pump in your ice maker is responsible for bringing water from the reservoir to the freezing components to make the cubes.

A blockage in your water pump will completely prevent your ice maker from creating ice, which may cause knocking. Luckily, this issue is incredibly simple to fix on your own.

Using the user manual, determine where the water pump and lines are on in your ice maker. Remove the wires and any water filters to determine if there is stuck debris. Debris comes in many forms, whether it be dirt, dust, or minerals from hard water.

Using vinegar, lemon juice, and a toothbrush, scrub the pieces until all of the debris has been removed. You will also want to check the drain pump for blockages, as a consistent blockage can cause the motor to overwork itself.

When to Call for Repairs

By now, you should know what sounds are typical for an ice maker to make and what sounds are likely to mean there could be a problem hiding within the unit.

Knowing when it’s time to call for repairs can help you to prolong the life of your ice maker without having to buy a new one. The most important part we’ll discuss is the compressor, as it’s essential to the ice maker’s operation.

1. Compressor Concerns

As earlier mentioned, knocking from the compressor could mean that it’s turning on and off, but it could also be something more sinister that requires the attention of a professional. Consistent knocking is a clear sign that the compressor is either lacking refrigerant or is faulty.

The reason as to why you’ll need to call for repairs with a faulty compressor is because the process requires recharging the refrigerant. This fluid is highly regulated by the EPA (Environmental Protection Act) and is only accessible by licensed professionals.

At this point, your best bet is to call a service technician to diagnose the problem in-person and provide you with a consultation.

2. Broken Water Pump

If you previously checked your water pump and didn’t find any blockages or debris, it could be that the pump is faulty. Typically, this issue will present with both knocking and the inability to make ice.

Unfortunately, a broken water pump means that water cannot move from the reservoir to the ice molds.

Similar to your compressor, replacing a water pump is something that should be done by a professional, as it requires wiring and experience with parts. Depending on the cost of your ice maker, it can be more beneficial to invest in a new one rather than pay for repairs and labor.

3. Faulty Manufacturing

When a manufacturer makes a product, they are typically creating hundreds of thousands (if not millions) of products daily in their factories. Out of all of these items, there are prone to be a few hundred with manufacturing defects. This reason is why companies have manufacturer’s warranties to protect the consumer against issues for at least three to six months.

Even though we would like to assume you received a fully functioning ice maker, knocking sounds could also mean that the unit is defective. Luckily, if you have just purchased the appliance, you should still be covered by the manufacturer’s warranty.

Most companies will allow you to return the product free of charge instead of a free replacement. On the other hand, if you are well past your warranty date and are experiencing knocking, we highly recommend bringing the ice maker to a repairperson for a full diagnostic.

As there are plenty of small components that rely on one another to produce ice, there could be numerous problems happening within the unit. For example, a clogged water line could cause stress on the water pump, which would then put pressure on the motor.

Pro Tip: Restart the Device

You would be surprised at the sheer amount of people who can troubleshoot and repair appliance issues by turning them off and on again. With an ice maker, you’ll want to make sure you turn it off, unplug the device, and then leave it turned off for several hours. The reason for this is because if ice is anywhere that it’s not supposed to be, you’ll want to let it thaw out.

Once you have allowed time for the ice maker to defrost, you can then plug it back in and turn it back on. Refill the water reservoir with cool to cold water and give the device 24 hours to continue making ice. If the knocking sound persists, it’s undoubtedly time to call in the professionals.

Final Thoughts

When you’re asking, why does my ice maker make a knocking sound, there are several issues it could be encountering. From insufficient water levels to a faulty water pump, there’s a lot to consider.

As a homeowner with minimal experience repairing appliances, you may want to opt for professional assistance as soon as possible.

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