Troubleshooting Reverse Osmosis Pumped Display Codes

Below are the Readout and Error Codes you might see displayed on your pumped reverse osmosis system.

For product codes RO-DEN-PMP |RO-PMP | RO-HP-PMP


CODE DISPLAYED: F / Flush

1. The power indicator light comes on when the machine is turned on, and it
flushes automatically for 30 seconds.

2. After 4 hours of cumulative water production, if there is no flushing in
the middle, it will automatically flush for 18 seconds.

3. After exiting from the water shortage program, it will automatically flush
for 5 seconds.

4. The lower two digits of the small digital tube display the remaining
backwash time, and the clock symbol flashes once a second.

5. Press the strong flush button to force flush for 30 seconds;
(The pump starts up, the water inlet valve opens, and the
flushing valve opens).

CODE DISPLAYED: E3

The following is what E3 error codes relate to on the RO-PMP electronic display

Low or No Inlet Water Pressure

If the water supply to the RO unit is turned off or very low, the pump can’t build enough pressure.

Faulty Pump

A malfunctioning pump can restrict flow 

Blocked or Clogged Filters

Pre-filters (sediment or carbon) might be clogged, restricting flow to the membrane.

 Faulty Pressure or Flow Sensor

The sensor that monitors pressure or flow may be defective or disconnected.

Airlock or Leaks in the System

Air in the pump or tubing can affect pressure readings.

Power Supply Issues

Inconsistent voltage to the pump can cause errors during operation.

CHECK 1) Inlet Water Supply

Make sure the water valve is fully open.

Ensure there is sufficient water pressure (> 40 PSI is typically required).

CHECK 2) Inspect Filters

Replace sediment and carbon filters if they haven’t been changed recently (usually every 6–12 months).

CHECK 3) Reset the System

Turn off the system and unplug it for a few minutes.

Restart and observe if the error returns.

CHECK 4) Check the Pump

Listen for normal pump operation.

If it’s silent or buzzing without pressure, the pump might need replacement.

CHECK 5) Examine Wiring and Sensors

Look for any loose or disconnected wires around the pressure sensor or control board.

CODE DISPLAYED: E6

This situation is caused by low inlet water pressure or insufficient inlet flow, resulting in the system working continuously for six hours without stopping due to full water, then displaying “6” character alarm. To check for insufficient inlet flow see below

CHECK 1) Remove pipe from inlet on lower housing:

Does water come out of the tube? If not then (a) check your mains water supply (b) If there is mains water, check the connection from the water supply to the filter. 

Locate the T bar tap (that sits on the copper pipe). Turn the T bar tap all the way in and out two or three times. (Don't overforce it. Just turn it fully in and out).

This is to clear any possible blockage inside the pipe (scale can build up and block the flow into the pinhole)

CHECK 2) ARE ALL THE CONNECTIONS BETWEEN THE WATER SUPPLY AND ALL OPEN

i) Check the "blue tap" shut off valve is ON (if you have one fitted)

ii) Check and correct any kinks in the feed pipe.

CHECK 3)  If there is no water in the tank (shake it to check) after 12 consecutive hours of water production, it means the RO is malfunctioning and has entered the maintenance procedure. 

The buzzer / alarm / beeps sounds rapidly.

(The pump stops, the water inlet valve closes, and the flushing valve closes)

The TDS value is not measured or displayed during this time.

Please go through this Process of Elimination

CODE DISPLAYED: 8 / Work

1. When the high-pressure switch detects that the water pressure in the tank is lower than the set value, the pure water machine enters the water production process.

2. The lower two digits of the small digital tube display the current TDS value.
The upper limit of TDS is 100PPM. If it exceeds 100PPM, the symbols "100" and "OVR" will flash alternately.

3. The probes and computer board have already been paired correctly so do
not change their postion.

4. TDS measurement can be susceptible to interference, so please
install the probe into the pipeline for measurement, otherwise the accuracy can be
affected. 

5. Any air bubbles in the pipeline will affect the TDS read's accuracy.


CODE DISPLAYED: 8 / Full

1. When the high-pressure switch detects that the water pressure in the tank reaches the set value, the pure water machine enters the "water full" process.

(The pump stops, the water inlet valve closes, and the flushing valve closes)

2. The display shows the last measured TDS value at the time of water production or
flushing.

CODE DISPLAYED: 8 / Lack

1. When the low-pressure switch detects that the incoming "raw water" pressure is lower than the set value, the pure water machine enters the "water shortage" program and the buzzer / alarm / beep sounds.

(The pump stops, the water inlet valve closes, and the flushing valve closes)

2. The TDS value is not measured or displayed during this time.

Keywords

Issues Problems Beeping Display readout errors alerts