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, it will automatically flush for 18 seconds.

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

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

5. This code will also display if you force flush the pumped RO unit. To force flush: press and hold the flush button firmly for 30 seconds. The pump will start, the water inlet valve will open, and the flushing valve will open.

We recommend force flushing the unit if it hasn't been used for a few days or more, if the water tastes or smells unusual after standing, straight after a filter or membrane change, or as part of routine periodic maintenance. Then empty the tank at least twice and let the tank refill for a third time before trying the water again.

CODE DISPLAYED: E3

The E3 error code might be caused by one or more of the following issues: Check each issue one at a time. (How to check is below.)

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 (should be changed every 6 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 electrically while without any 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, then displaying the “6” 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 RO starts the filtering process - ie starts to fill the tank.

2. The lower two digits of the digital display show the current TDS (Total Dissolved Solids) value.

The upper limit of TDS is 100PPM.

If TDS 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 position.

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 the tank is full the RO 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 too low, 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.

CODE DISPLAYED: 7 / OUA

This error code indicates the reverse osmosis membrane is worn out and you need to replace it.

But first check the probe is not faulty.

How to check the RO TDS probe

1. Locate the TDS probe. It sits in a small fitting on top of the third vertical housing.
2. Relieve pressure. Shut off the inlet valve and let the housing depressurise so water doesn't spray out.
3. Prepare a cloth. Dampen a soft cloth with diluted vinegar or isopropyl alcohol. Don't use abrasive scrubbers, as they can scratch the sensor contacts.
4. Clean the outside first. Wipe around the connector and housing cap so grit doesn't fall into the socket.
5. Remove the probe. Hold it by the plastic base, not the metal tip, and gently pull it out.
6. Clean the sensor tip. Gently wipe the two metal contacts to remove scale or residue. Buildup here is the most common cause of inaccurate readings.
7. Clean the socket. Wipe out the port so the probe can seal and make good contact.
8. Reinsert the probe. Push it firmly into place and reopen the inlet valve.
9. Check the reading. Power the system on and confirm the display shows a stable, sensible TDS value rather than an error or erratic number.

See full  RO troubleshooting guide

Keywords

Issues Problems Beeping Display readout errors alerts