When using a Liliumfaucet under-sink sparkling water dispenser, some users may see an E4 error code on the display. When this happens, it is natural to worry that the machine may be defective. However, in most cases, E4 does not mean the product is damaged. It is more commonly a self-protection warning from the machine.

When the sparkling water dispenser detects insufficient inlet water flow, low inlet water pressure, poor ventilation, or excessive continuous water dispensing, the system may automatically stop working and enter protection mode. This helps protect the internal system from overheating or potential damage.

In many cases, the E4 error can be resolved by checking the water supply, water pressure, CO₂ pressure, and ventilation conditions. As long as the installation environment and water supply are stable, the machine can usually return to normal operation.

This article explains the common causes of the Liliumfaucet sparkling water dispenser E4 error, how to fix it, and how to troubleshoot the issue step by step.

 

What Does the E4 Error Mean?

E4 is a protection warning on the Liliumfaucet sparkling water dispenser. It usually appears when the machine detects that the inlet water flow is too low, or when the water supply cannot keep up with the water being dispensed.

After the E4 error appears, the machine will enter protection mode and temporarily stop working. This is designed to prevent the machine from continuing to operate under low-water, low-flow, or poor-ventilation conditions, which may lead to overheating or internal damage.

In simple terms, E4 is not a regular alarm, and it does not necessarily mean the machine is broken. It is a reminder that the current water supply, pressure, or ventilation conditions may not be suitable for continuous operation.

When the machine shows E4, we recommend checking the following first:

• Whether the inlet water flow is normal
• Whether the inlet water pressure is stable
• Whether the filter or RO system is supplying water smoothly
• Whether the machine has enough ventilation space
• Whether the CO₂ pressure is set correctly

 

Common Causes of the E4 Error on Liliumfaucet Sparkling Water Dispensers

1. Insufficient Inlet Water Flow

Insufficient inlet water flow is one of the most common causes of the E4 error.

The sparkling water dispenser requires a stable water supply during operation. If the water flow from the filter, RO system, or inlet tubing is too low, the machine may not be able to refill water in time. When the machine detects insufficient internal water supply, it will enter protection mode and display E4.

This may happen in the following situations:

• The filter has been used for a long time and may be clogged
• The RO system has a slow water output
• The inlet tube is bent or compressed
• The water supply valve is not fully open
• The inlet connection is not smooth or secure

If you notice that the water flow becomes weak, or the E4 error appears after dispensing sparkling water for a short time, please check the inlet water flow first.

 

2. Low Inlet Water Pressure

The recommended filtered water inlet pressure for the Liliumfaucet sparkling water dispenser is around 30–45 PSI / 2–3 bar.

If the inlet pressure is lower than the recommended range, the machine may not receive a stable water supply while cooling or producing sparkling water. This can trigger the E4 protection mode.

This is especially important for users connecting the machine to an RO system. The output pressure and flow rate of the RO system should be checked carefully. Even if the main household water pressure is normal, the filtered water pressure entering the sparkling water dispenser may still be too low.

We recommend checking:

• The actual water pressure after filtration
• Whether the RO system output is stable
• Whether a pressure tank or improved water supply method is needed
• Whether there is any blockage or leakage in the tubing or fittings

Stable inlet water pressure is essential for normal operation.

 

3. Continuous High Water Usage Causing Slow Refilling

If a large amount of sparkling water or chilled water is dispensed continuously within a short period of time, the internal water supply may not refill quickly enough.

When the dispensing speed is faster than the refill speed, the machine may detect insufficient water supply. To protect the internal system, it may stop working and display the E4 error.

This does not necessarily mean the machine is defective. It usually means the machine has entered protection mode.

If E4 appears after continuous heavy use, we recommend pausing for a while to allow the machine to refill and cool down. Then restart the machine and check whether it returns to normal.

 

4. High Cabinet Temperature or Insufficient Ventilation Space

The Liliumfaucet sparkling water dispenser is usually installed under the kitchen sink. If the cabinet space is too small, poorly ventilated, or the back of the machine is too close to the wall, the heat generated during operation may not be released properly. This may trigger the protection mode.

We recommend leaving at least 10 cm of ventilation space between the back of the machine and the wall. Do not place the machine tightly against a wall, cabinet panel, or other equipment. Avoid storing too many items around the machine.

If the machine works normally when the cabinet door is open, but the E4 error appears more often when the cabinet door is closed, the issue is likely related to poor ventilation.

Recommended solutions include:

• Open the cabinet door and test the machine for a period of time
• Increase the ventilation space behind the machine
• Avoid storing cleaning products or other items around the machine
• Keep the air inside the cabinet circulating
• Add ventilation holes or improve cabinet airflow if necessary

Good ventilation can greatly reduce the chance of E4 errors.

 

5. Incorrect CO₂ Pressure Setting

Incorrect CO₂ pressure may also affect the normal operation of the sparkling water dispenser.

Liliumfaucet recommends using food-grade CO₂ and setting the regulator pressure within the range of 65–80 PSI. If the pressure is too high, it may affect the internal mixing of water and gas, as well as the normal operation of the machine. If CO₂ is not entering the machine properly, the carbonation effect may also become weak.

Please check the following:

• Whether the CO₂ cylinder is fully open
• Whether there is enough CO₂ in the cylinder
• Whether the regulator pressure is within 65–80 PSI
• Whether the regulator direction is correct
• Whether the regulator and 5/16" connection are properly connected
• Whether the connector is overtightened and blocking gas flow

CO₂ pressure that is too high or too low can affect the user experience. Please adjust it within the recommended range.

 

Quick Solutions for the E4 Error

Step 1: Turn Off the Machine and Restart It

When the machine displays E4, first turn off the power and wait a few minutes before restarting it.

Steps:

1. Turn off the machine
2. Wait for a few minutes
3. Confirm that the water supply is open
4. Make sure the inlet tube is not bent or compressed
5. Turn the machine back on
6. Check whether the E4 error appears again

If E4 only appears occasionally and the machine works normally after restarting, repair is usually not required. We recommend continuing to monitor the machine and checking whether the installation environment meets the requirements.

 

Step 2: Check Whether the Water Supply Is Normal

Checking the water supply is a key step in troubleshooting the E4 error.

Please confirm the following:

• The water supply valve is fully open
• The filter is not clogged
• The RO system output is stable
• The inlet tube is not bent or compressed
• The inlet connection is secure
• Room-temperature water and chilled water can be dispensed normally

If the room-temperature water or chilled water flow is very weak, the machine may not be receiving enough water. The water supply issue should be resolved first.

If a filter or RO system is connected, check whether the filter cartridge needs to be replaced. A clogged filter can significantly reduce water flow and cause delayed refilling.

 

Step 3: Check the Inlet Water Pressure

Please confirm whether the filtered inlet water pressure is around 30–45 PSI / 2–3 bar.

If the water pressure is below this range, the machine may not operate steadily. When using an RO system, do not only check the main household water pressure. You also need to check the actual water pressure after the RO system.

If the inlet water pressure is insufficient, you may consider:

• Checking whether the filter is clogged
• Checking whether the RO system output is too slow
• Confirming that the water supply valve is fully open
• Checking whether the tubing is bent or blocked
• Consulting an installer to see whether a pressure tank or improved water supply method is needed

Only with stable inlet water pressure can the machine cool and produce sparkling water properly.

 

Step 4: Check the Ventilation Space Around the Machine

If the water pressure and water flow are normal, but the E4 error still appears frequently, please check the ventilation environment.

Please confirm:

• There is at least 10 cm of ventilation space behind the machine
• The machine is not tightly against a wall or cabinet panel
• There are not too many items stored around the machine
• Air can circulate around the machine
• The cabinet temperature is not too high

You can open the cabinet door and let the machine run for a period of time. If E4 occurs less often with the cabinet door open, the issue is likely related to insufficient ventilation.

The sparkling water dispenser needs to release heat during operation. If the ventilation space is too small, the internal temperature may rise and trigger protection mode.

 

Step 5: Check the CO₂ Pressure

The CO₂ system is also important for normal operation.

Please check the following:

• The CO₂ cylinder is open
• The CO₂ cylinder is not empty
• Food-grade CO₂ is being used
• The regulator is set to 65–80 PSI
• The regulator and 5/16" connection are properly connected
• The CO₂ tubing is not bent, blocked, or leaking
• The regulator connector is not overtightened

If the sparkling water is weak, has no bubbles, or the machine only releases gas without water, please check whether CO₂ is entering the machine properly.

We do not recommend setting the CO₂ pressure too high. Excessive pressure may affect machine operation and may also create potential risks.

 

How to Tell Whether the E4 Error Is Caused by Water Pressure or Ventilation

You can make an initial judgment based on when and how the E4 error appears.

If E4 mostly appears after continuous dispensing, it is usually related to refill speed.
If E4 mostly appears after the cabinet door is closed and the machine runs for a while, it is usually related to ventilation.
If the sparkling water tastes weak, the CO₂ system should also be checked.

 

E4 Error Troubleshooting Checklist

When your Liliumfaucet sparkling water dispenser shows E4, we recommend checking the following in order:

1. Check whether the machine is powered on normally
2. Check whether the water supply is open
3. Check whether the filter or RO system is supplying water normally
4. Check whether room-temperature water and chilled water can be dispensed steadily
5. Check whether the filtered inlet water pressure is 30–45 PSI
6. Check whether the CO₂ pressure is 65–80 PSI
7. Check whether there is at least 10 cm of ventilation space behind the machine
8. Check whether the cabinet is too hot or poorly ventilated
9. Turn off the machine and restart it to see whether the E4 error disappears

Following this checklist can help you find the real cause of the E4 error more quickly.

 

When Should You Contact After-Sales Support?

If you have confirmed that the water pressure, water flow, CO₂ pressure, and ventilation are all normal, but the E4 error still appears frequently, please contact Liliumfaucet Support for further assistance.

To help us diagnose the issue more quickly, please provide the following information:

• Order number
• Machine serial number or a photo of the machine label
• Photos of the installation environment
• Current water pressure reading
• CO₂ pressure reading
• A video showing the E4 error
• Videos showing the room-temperature water, chilled water, and sparkling water flow

This information will help our support team determine whether the issue is related to water supply, CO₂ settings, installation conditions, or whether the internal components need further inspection.

 

FAQ

Does E4 mean the machine is broken?

Not necessarily. In most cases, E4 is a protection warning. It is usually related to water flow, water pressure, continuous dispensing, or ventilation. Once the water supply and ventilation conditions return to normal, the machine can usually continue working.

 

If the E4 error disappears after restarting, does the machine need repair?

If E4 only appears occasionally and the machine works normally after restarting, repair is usually not needed.

However, we recommend checking the inlet water flow, water pressure, and ventilation conditions to help prevent the issue from happening again.

 

Why does the E4 error happen less often when the cabinet door is open?

This usually means the cabinet does not have enough ventilation.

The sparkling water dispenser generates heat during operation. If the cabinet is closed and air cannot circulate properly, the internal temperature may rise and trigger protection mode. We recommend improving the ventilation space around the machine, especially by leaving at least 10 cm of space behind it.

 

Can an RO system be connected to the sparkling water dispenser?

Yes. An RO system can be connected to the Liliumfaucet sparkling water dispenser, but the RO system must provide enough water pressure and flow.

The recommended filtered inlet water pressure is around 30–45 PSI / 2–3 bar. If the RO system output is too slow, the machine may not refill quickly enough, which can cause E4.

 

What CO₂ pressure should I use?

We recommend using food-grade CO₂ and setting the regulator pressure within 65–80 PSI.

Low pressure may affect the carbonation level, while excessive pressure may affect machine operation and create potential risks. Please adjust the pressure within the recommended range according to actual use.

 

Conclusion

When your Liliumfaucet sparkling water dispenser shows an E4 error, it does not necessarily mean the machine is defective. E4 is usually a self-protection warning caused by insufficient inlet water flow, low water pressure, continuous heavy water use, incorrect CO₂ pressure, or poor cabinet ventilation.

We recommend checking the inlet water flow, water pressure, CO₂ pressure, and ventilation environment first. As long as the installation environment and water supply conditions are stable, the machine can usually return to normal operation.

If the issue continues, please contact Liliumfaucet Support. We will review your installation details and videos to help you further troubleshoot the problem and provide after-sales support.