How To Use Momcozy S12 Pro

If you’re new to the Momcozy S12 Pro and are looking for guidance on how to use it, then you’re in the right spot!

In this comprehensive guide on how to use Momcozy S12 Pro to its fullest, I’ll walk you through each step, from the components to assembly to how it operates so you can feel confident while using this great wearable breast pump.

I think the Momcozy S12 Pro is a stands out in the Momcozy breast pump range for its large LED screen with an in-built timer that gives you more control over your pumping experience.  This powerful pump comes with 9 suction levels and 3 modes for efficient milk expression. As well comes with additional features such as its cushioned breast shield/flange for enhanced comfort.

So, whether you’re just beginning your journey with Momcozy wearable breast pumps or you’re a seasoned user looking to elevate your pumping experience, this guide acts as your passport to a hassle-free and successful pumping journey with the Momcozy S12 Pro.

And if you are still contemplating purchasing the Momcozy M5, then make sure to check out my full Momcozy S12 Pro Review!

how to use momcozy s12 pro

Momcozy S12 Pro Inclusions

When you first receive your Momcozy S12 Pro breast pump, it’s essential to familiarize yourself with the contents of the package.

This will ensure that you have all the necessary components to set up and start using your breast pump effectively.

When you purchase a Momcozy S12 Pro pump, included in your kit is:

Single Wearable Pump Kit

  • Pump Motor * 1
  • Milk Collector (180ml) * 1
  • Silicone Flange (24 mm) * 1
  • Silicone Diaphragm * 1
  • Duckbill Valve * 2
  • Linker * 1
  • Bra Adjustment Buckle * 1
  • USB Cable * 1
  • Storage Bag * 1

Double Wearable Pump Kit

  • Pump Motor * 2
  • Milk Collector (180ml) * 2
  • Silicone Flange (24 mm) * 2
  • Silicone Diaphragm * 2
  • Duckbill Valve * 4
  • Linker * 2
  • Bra Adjustment Buckle * 2
  • USB Cable * 2
  • Storage Bag * 2

I highly recommend taking a moment to check all these components are included in your package. If you find anything missing or damaged, then reach out to Momcozy’s customer support for assistance.

If you’re using a second-hand pump, then again, I highly recommend checking all the parts to ensure that they are there and intact. Additionally, I recommend considering replacing items like valves and breast shields in accordance with Momcozy’s maintenance guidelines.

While buying new valve membranes, valves, flanges, and breast shields may involve an extra expense, it really is important for maintaining the hygiene and effectiveness of your pump during.

Furthermore, you will need to make certain you have the appropriate flange size that matches your nipple size. You may need to purchase these separately.

momcozy s12 pro components

Momcozy S12 Pro Components

Before you start using the Momcozy S12 Pro breast pump, it’s essential to have a clear understanding of its components and controls.

Here’s an in-depth overview:

Breast Pump Motor: The main unit of the Momcozy S12 Pro contains the motor and power source. It’s the heart of the pump, responsible for creating the suction necessary for milk expression.

Milk Collection Cup: These are the containers that collect the expressed breast milk.

Breast Shield/Flange: A breast shield, also known as a flange, is the funnel-shaped part that fits over your breasts. They come in various sizes to accommodate different breast shapes. Properly fitting breast shields is crucial for comfort and efficient milk expression.

There are also different flange sizes available that insert into the breast shield to change the sizing.

Diaphragm: This is a small flat, circular membrane which is part of the valve system.

Linker: This connects the diaphragm, valve, and flange together.

Valve: This component helps create a one-way valve system that controls the flow of milk from your breast into the collection bottle.

USB Cable: The USB charger is plugged into your pump motor and power source to recharge your breast pump.

Power Button: The power button is used to turn the breast pump on and off.

LCD Screen: The LCD screen displays important information, such as suction level, pumping mode, and battery status.

Suction and Mode Control Buttons: These buttons allow you to adjust the mode and suction level according to your comfort and milk flow.


Properly assembling the Momcozy S12 Pro breast pump is vital for its effective performance.

I love that when you purchase your pump it arrives pre-assembled in the box as I think it helps to provide a clear understanding of its configuration.

However, before use, just know that it’s necessary to disassemble the pump and sterilize it.

Maintaining proper hygiene while setting up your Momcozy S12 Pro breast pump is essential for you and your baby.

Here are some hygiene tips to follow:

  • Wash your hands thoroughly before touching any pump components.
  • Disassemble the pump parts that come into contact with your breast milk (breast shields, flanges, valves, membranes, and collection bottles) after each use and wash them with warm, soapy water. Rinse and air dry or use a clean, dry cloth or paper towel.
  • Sterilize these components regularly, especially if you are using the breast pump multiple times a day. You can do this by boiling them for a few minutes or using a steam sterilizer.
  • Ensure that the breast pump unit and tubing remain dry and free from moisture or milk residue.
  • Store your breast pump and its components in a clean, dry place when not in use to prevent contamination.

Now once your breast pump has been cleaned and sterilized you can look to reassemble it ready for your first pumping session.

Here’s a step-by-step guide to help you reassemble your S12 Pro:

Step 1

Wash your hands thoroughly with soap and water before handling any components.

Step 2

Put the silicone diaphragm into the linker. Ensure you push down for a good seal.

how to assemble momcozy s12 pro step 1

Step 3

Connect the silicone valve to the end of the linker, again making sure it has a sufficient seal.

how to assemble momcozy s12 pro step 2

Step 4

Attach the assembled linker part to the milk collector cup and align the ‘ear’ notch of the linker with the inner groove of the milk collector cup. It should click into place, but always check to ensure a secure fit.

how to assemble momcozy s12 pro step 3

Step 5

Connect the flange/breast shield with the main body of the collection cup.

I also like to ensure a good seal by pressing my thumbs around the rim.

how to assemble momcozy s12 pro step 4

Step 6

Press in the pump motor to the top of the collection container.

how to assemble momcozy s12 pro step 5

Step 7

Turn on the Momcozy S12 Pro breast pump by pressing the power button. You will see the LCD screen light up.

Now, your breast pump is ready for pumping breastmilk, but first let’s cover the the pump’s controls, including the suction level and mode settings so you can use your pump with confidence.

Buttons and LED Screen

There are 4 buttons used to operate the Momcozy S12 Pro, with an LED screen that provides valuable information during your pumping sessions.

Here’s what you need to know controlling your breast pump:

On/Off Button: You can turn your pump on and off or pause it with the power symbol button.

To turn your pump on or off, long press the power button.

Short press the power button to pause. You can then press any button to un-pause and continue your pumping session.

Suction Level: The screen displays the current suction level. You can typically increase or decrease this level to find the right intensity for your comfort and milk expression.

The + button will increase the suction level and the – button will decrease it.

The level you are on will be displayed by a number on the screen.

Pumping Mode: There are three pumping modes on the S12 Pro, stimulation mode for stimulating letdown, expression mode for efficient milk removal, and a mixed mode which is a combination of the stimulation and expression modes.

The LCD screen will indicate the current mode.

The heart symbol represents the stimulation mode and the droplet symbol represents the expression mode. When both symbols are visible then the pump is in the mixed mode.

You can switch between the three modes with the circular arrow button.

Timer: I love that the S9 Pro comes with an inbuilt timer. Once you start your pumping session the timer will be activated. This allows you to easily keep track of your pumping session and adjust as needed.

Battery Status: The battery life of the S12 Pro breast pump is displayed by 4 white bars, when fully chargers, on the bottom right of your display (under the timer). Low battery will be indicated by a blinking bar.

Error Messages: The LCD screen may display error messages if there are any issues with the pump, such as a blocked tube or low battery.

Please note when using your pump, the LED light will turn off after 15 seconds, this is to help increase discretion. To activate the display light just press any button.

momcozy s12 pro led screen

Suction Levels and Modes

The Momcozy S12 Pro is equipped with three modes and nine distinct suction levels, offering versatility to cater to your specific needs.

These three pumping modes include a stimulation mode, which initiates breastmilk stimulation, an expression mode for efficient milk removal, and a mixed mode that combines elements of both for optimal expression.

The stimulation mode typically has a faster rhythm to encourage letdown at the beginning of your pumping session, while the expression mode adopts a slower and more consistent suction pattern for the primary phase of pumping.

The mixed mode blends features from both the stimulation and expression modes, providing additional options to customize your pumping experience.

Throughout all three modes, you have the flexibility to adjust the suction strength using the nine different levels, ranging from gentle to strong.

I highly recommend experimenting with various levels to discover what feels both comfortable and effective for you. For me, I prefer to start with a lower suction level and gradually increase it until you strike the right balance. It is much more comfortable this way.

Also keep in mind that the highest suction setting may not necessarily yield the most advantageous results for milk extraction, as it’s closely tied to your personal comfort levels.

momcozy s12 pro

Using the Momcozy S12 PRO

Once you’re ready to start pumping with the Momcozy S12 Pro, it is a relatively straightforward process.

Here are the key steps to follow when using the Momcozy S12 Pro:

Step 1

Wash Your Hands: Clean your hands thoroughly with soap and water to maintain hygiene.

Step 2

Assemble the Pump: Ensure that you have sterilized and assembled your pump ready for use.

Step 3

Place the Breast Shields: Position the breast shields over your breasts, ensuring that your nipple is centered and can move freely within the shield. Create a gentle seal by pressing the shield slightly against your breast.

Step 4

Secure your Pumping Bra: One of the main benefits of the S12 Pro is that it is a wearable pump, therefore it can fit snugly into your bra without any cords. So, once you have a secure fit over your nipple, ensure that your bra is also secured. You’ll want to make sure that the bra you use is stretchy and your pump fits in it nicely. Not too loose and not too tight. 

Step 5

Turn On the Pump: Press the power button on the Momcozy S12 Pro to turn it on. The LCD screen will light up, and you’ll be able to see the current settings.

Step 6

Select Pumping Mode and Adjust Suction Level: Choose the pumping mode that suits your needs.

Start with the massage mode to stimulate letdown.

You can also adjust your suction level on the massage mode. I recommend starting with a level 2 or 3 on massage mode for around 2 minutes and then once your milk starts flowing, switch to the expression mode for efficient milk removal.

On the expression and mixed modes, I recommend beginning with a low suction level and gradually increasing it until you find a comfortable yet effective setting.

You should feel a gentle pulling sensation, not pain.

Your expression/mixed mode should for around 15 to 20 minutes. 

Step 7

Monitor: During your session it is vital to keep an eye on your milk flow. This will allow you to trouble shoot any issue that arises such as your nipple shield moving or low suction power.

Step 8

Turn off the Pump: Once you have finished with your milk extraction turn off the pump by pressing on the power button. If you forget to turn off the pump, it does have a 30 minute auto shut off.

Step 9

Remove the Pump: Use your fingers to break the seal between the flange and your breast. Lean slightly forward when removing your pump to prevent any spillage.

Step 10

Pour the Breast Milk into A Storage Container: You will not be able to store your milk in the collection cups, thus you will need to transfer the milk into a suitable storage container.

My guide of how to store breast milk is a great place to start if you’re new to milk storage.

To transfer the breast milk. First remove the motor and then carefully pour the milk into your storage container. I do love that Momcozy S12 Pro comes with a handy pouring spout to make this easier.

Step 11

Clean Your Pump: Once finished with your pumping session you will need to wash all the parts that have come into contact with your breast milk to ensure the hygiene of your pump.

Step 12

Check the Battery Levels: After you’ve finished your session, I highly recommend checking the remaining battery life on the pump. Recharge the pumps if needed so they are ready for your next use. The charging port is located at the back of the pump motor.

Step 13

Store: Once clean, store your pump in a safe and secure location ready for the next use.

momcozy s12 pro battery port

Troubleshooting Common Issues

Although the Momcozy S12 Pro boasts reliability as a breast pump, users may encounter common issues that can disrupt their pumping experience.

Here, you’ll find solutions and troubleshooting tips for addressing these common problems associated with the Momcozy S12 Pro.

Low Milk Output:

  • Ensure that you’re using the correct breast shield size that matches your nipple.
  • Adjust the suction level and mode to align with your comfort and milk flow.
  • Experiment with gentle breast compressions or massaging techniques during pumping to stimulate milk flow.
  • Maintain proper hydration, a balanced diet, and sufficient rest to support milk production.

Pain or Discomfort:

  • Evaluate the fit of the breast shield to ensure it’s neither too tight nor too loose.
  • If the suction level causes discomfort, decrease it.
  • Prior to pumping, consider applying a lanolin-based nipple cream or using a warm compress.
  • Pay careful attention to proper breast positioning to prevent nipple irritation against the shield.

Loss of Suction:

  • Thoroughly inspect all pump components, including valves and membranes, to confirm correct assembly and secure sealing.
  • Examine the tubing for potential kinks or blockages.
  • Promptly replace any worn-out or damaged parts, such as valves and membranes.
  • Ensure the breast shields are securely attached to your breasts.

Milk Overflow:

  • Monitor the milk flow during pumping and switch off the pump when the collection cups reach 4oz.
  • Maintain the pump at an appropriate angle to prevent milk overflow.

Noise or Vibration:

  • Verify that all components are securely assembled and in good condition.
  • Place the breast pump on a stable and level surface to minimize vibrations.
  • If excessive noise or vibration persists, consider reaching out to Momcozy customer support, as it may indicate a malfunction.

While many issues can be resolved through troubleshooting, sometimes you may need further assistance.

In that case, I recommend reading through the Momcozy S12 Pro manual and if that doesn’t help contacting Momcozy’s customer support to assist you with any issues you may encounter while using the Momcozy S12 Pro breast pump.

They can provide expert advice, troubleshooting assistance, and information on warranty coverage and replacement parts to ensure you have a seamless pumping experience.

You can contact Momcozy support at

Watch The Video

Prefer to watch my how to use Momcozy S12 Pro video? Then check out my Momcozy S12 Pro assembly and how to use video below!

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Final Thoughts

I believe the Momcozy S12 Pro is an excellent wearable breast pump designed for convenience, comfort, and efficiency. However, the key to achieving success lies in mastering the use of the Momcozy S12 Pro to ensure your utmost comfort and effective milk expression.

From gaining a deep understanding of its components and controls to establishing a consistent maintenance and hygiene routine, I trust that this guide has equipped you with a comprehensive, step-by-step approach to operating your Momcozy S12 Pro breast pump.

As always keep in mind that practice and patience play crucial roles in this journey. If you encounter any challenges along the way, don’t hesitate to seek assistance from a lactation consultant, healthcare professionals, or the dedicated customer support team at Momcozy. They are there to support you.

momcozy s12 pro how to use