Why is the the Low Water Light active (Solid) on the Solar Pump Controller?

1. Remove the Red Bridge Wire

From the factory, there is a red wire bridging the WC and WH terminals. This must be removed when you use a low water sensor or flow switch.

If the red wire is left connected, it may cause the controller to get mixed signals. It may also ignore or override the signals from the low water sensor or flow switch.

2. Check the Placement of the Low Water Sensor

The most common reason for a Low Water light to be on and solid, is that the sensor is not under water.

For submersible pumps: the sensor must be mounted at least 1 metre above the pump inlet to provide proper protection.
- The sensor must be fixed in place vertically with the wire coming from the top of the sensor. Do not install it coming from the bottom and then running up towards the surface.
For surface pumps, a flow switch is typically used to protect the pump from running dry. This is to protect the pump if the water source runs dry, as well as the pump losing prime.
- Confirm that the flow switch is installed between the pump and the pressure switch assembly.
- Confirm that the flow switch is installed facing the correct direction and horizontally.
If a low water sensor is being use for a surface pump:
- It should be installed inside the tank or water source and not resting on the bottom or touching any sides or walls.
- Check that the sensor is installed in the correct orientation. Check the DC pump user manual for information on the correct way to install the sensor.

A sensor that isn’t fully submerged or is touching the tank wall might give false “no water” signals. Make sure the sensor is:

Hanging vertically.
Fully submerged in water.
Not floating freely.

Important:

If a low water sensor is sitting in air or only partially submerged, the controller thinks there is no water.
Use zip ties to secure the sensor to a pipe or pole.

3. Inspect the Sensor Wiring at the Controller

Open the pump controller and find the WC and WH terminals:

Confirm that the factory fitted loop wire has been removed from both the WH and WH terminals.
Ensure the low water sensor’s wires are correctly inserted into WC and WH terminals (there is no polarity to this wiring, either wire can go to either terminal).
Check for:
- Loose wires.
- Corrosion or oxidation on the terminals.
- Animal damage or cracked insulation.

Tighten and clean any poor connections.

4. Test the Low Water alarm function using a jumper wire

If you suspect the sensor might be faulty, place a loop wire between the WC and WH terminals.
- If the Low Water light starts flashing or turns off:
  - The low water sensor is not in water
  - Water is not being pushed through the flow switch
  - Or the switch/sensor is faulty and needs replacing

Important: Remove the jumper after testing — don’t leave it permanently installed.

5. Clearing the 30-Minute restart delay (If Applicable)

If the Low Water light is no longer solid and has begun flashing, this indicates that it has started a 30-Minute restart delay. This delay will start if the sensor was not submerged but now is.

The restart delay can be cleared two ways:
1. Wait 30 minutes — and it will restart the pump automatically.
2. Perform a manual reset:
  - Turn OFF the solar isolator.
  - Wait 30 seconds.
  - Turn it back ON.

6. Sensor Failure

If the sensor is underwater, the wiring is correct and not damaged, the loop wire test worked but the light stays on when the low water sensor or flow switch is installed, the sensor is faulty and need replacing.

Conclusion:
A solid Low Water light means the pump is shut down for protection due to a sensor reading "no water."
Check sensor depth, wiring, and remove the red bridge if present.
If all checks pass and the light is still on, the sensor may need replacing.

For further assistance, contact Commodore Australia’s Technical Support team for further assistance.

Phone 1300 669 256 or email support@commodoreaustralia.com.au