Garden irrigation / pump controller not working
An irrigation controller or garden pump won't run the zones/pump — points at the controller power, the solenoids/pump supply, or wiring in a wet outdoor environment.
Safety first
Isolate before working. Outdoor/wet-area wiring and any mains pump must be on suitable, protected circuits. Low-voltage solenoid wiring is common but the supply side is mains.
Isolate, lock out / tag out, and prove dead before working unless a live test is specifically required, authorised, and carried out under proper supervision. Always follow local regulations, your site procedures, and the equipment manufacturer's documentation.
Full detail — causes, the why, and common mistakes.
Likely causes
Ranked from most to least likely.
- 1
Controller has no power / failed
Most likelyThe controller's plugpack/supply is off or the controller has failed.
- 2
Solenoid / zone wiring fault
#2A broken/corroded solenoid wire or failed solenoid stops a zone.
- 3
Pump supply / protection tripped
#3A mains pump's circuit has tripped or lost supply.
- 4
Programming / schedule issue
Least likelyThe controller schedule, rain-sensor, or season setting stops it running.
Reports are saved on this device to reflect what you actually find.
Testing sequence
Work through one test at a time. Expected reading and what each result means.
Confirm the controller has power and check its schedule/rain-sensor settings.
Controller powered; schedule active (no rain-sensor hold).
Powered and set — check the solenoids/zones and pump supply.
No power or schedule/rain hold — restore power / correct settings.
View all expected readings at once
Fault-finding flowchart
The same logic as a decision tree.
- 1start
Irrigation/pump controller fault
→ step 2 - 2decision
Is the controller powered and the schedule active (no rain hold)?
Yes→ step 3No→ step 4 - 3decision
Do zones activate and (mains) pump have supply?
Yes→ step 5No→ step 6 - 4result
Restore power / correct schedule or rain-sensor settings.
- 5result
If a specific zone fails, it's that solenoid/wiring.
- 6result
Solenoid/zone wiring fault or pump supply tripped — rectify.
Common mistakes apprentices make
- Overlooking a rain-sensor or seasonal-adjust hold.
- Not checking the controller's plugpack/supply.
- Ignoring corroded outdoor solenoid wiring.
- Forgetting a mains pump is on its own protected circuit.
When to stop & escalate
Mains pump and supply-side work is licensed electrical. Low-voltage solenoid/controller wiring faults in wet areas should still be rectified to a suitable standard.
If you're past your competence, authorisation, or the safe limits of the job — stop and hand it on. There's no fault worth getting hurt over.
Related faults
No power to a shed or outbuilding
A shed or outbuilding has lost power — points at the sub-circuit/sub-board feeding it, the submain, a tripped protective device, or moisture.
Outdoor power point not working
An outdoor GPO is dead — often after rain — pointing at a tripped safety switch from moisture, a weatherproofing failure, or the outlet/run.
Pump motor runs but there's no flow
The pump motor runs normally electrically, but there's little or no flow/pressure — the electrics are fine, so the problem is hydraulic, priming, or direction.