Sensor Fault
Galcon Smart Irrigation Controller
Severity:What Does This Error Mean?
A Sensor Fault on your Galcon controller means the connected rain sensor, soil moisture sensor, or weather sensor is not communicating correctly. The controller may be suspending watering until the sensor issue is resolved.
Affected Models
- Galcon 9001
- Galcon 8054
- Galcon PC-48
- Galcon G-Pro Series
Common Causes
- Rain sensor wires are disconnected from the controller terminals
- Rain sensor disc is stuck in 'wet' position after prolonged rain (watering suspended)
- Sensor has been physically damaged by weather or UV degradation
- Sensor is not compatible with the controller model
- Soil moisture sensor probe has corroded
How to Fix It
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Check sensor wiring at the controller
Open the controller wiring panel. The sensor typically connects to dedicated 'SEN' or sensor terminals. Confirm both wires are securely connected.
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Bypass the sensor temporarily
Most Galcon controllers have a sensor bypass switch or setting. Bypass the sensor and run the system manually. If watering works in bypass, the sensor itself is the problem.
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Inspect the rain sensor disc
Rain sensors contain a hygroscopic disc that swells when wet and triggers the sensor. If it is stuck swollen after recent rain, allow it to dry in a sunny spot — it may take 24–48 hours.
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Check for physical damage
Examine the sensor housing for cracks, discolouration from UV, or debris. Replace if visibly damaged.
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Operate on sensor bypass if needed
If you need to water while waiting for a new sensor, set the controller to bypass mode. Remember to restore sensor control once the new sensor is installed.
When to Call a Professional
Only if the sensor needs physical replacement.
Galcon Sensor Fault
Sensors connected to a Galcon controller — most commonly a rain sensor — are meant to pause watering when it is already raining or when the soil is already wet. A sensor fault means this circuit is not working correctly.
The Stuck Sensor Problem
The most common post-rain scenario: the system works perfectly until heavy rain, then stops watering for days or weeks. The rain sensor’s hygroscopic disc absorbed water and swelled, signalling “rain detected” — but it dried out slowly (or not at all if damaged).
Quick fix: Set the controller to sensor bypass mode so your garden gets water while you sort out the sensor.
Frequently Asked Questions
Can I run my Galcon system without any sensor connected?
Yes — if you do not have a sensor or the sensor is faulty, set the controller to 'No Sensor' or 'Bypass' mode. The system will run purely on its programmed schedule.
My Galcon stopped watering after heavy rain and has not started again. Is the sensor stuck?
Almost certainly yes. The hygroscopic disc in rain sensors can take 1–3 days to dry out fully after heavy rain, especially in humid climates. The sensor bypass override lets you water manually in the meantime.