Several stations stopped working at the same time

What has gone wrong

Two or more stations went down together and the rest still run. That is rarely a coincidence — solenoids do not fail in pairs on the same weekend.

What they have in common is the wiring. Every station shares one common wire, usually white, that runs out to the valves and back to a single terminal. Break it at one point and everything downstream of the break goes dead at once, while everything upstream carries on as normal. That is the fault, most of the time.

The other possibility is the controller. If the dead stations are next to each other on the terminal strip — 3, 4 and 5 rather than 1, 4 and 7 — you may have lost an output bank rather than a wire.

If every station is dead rather than several, this is the wrong page. Go to nothing works at all.

Why this happens in Perth

This is a dug-through-wire town. Sandy soil is easy to dig, so retaining walls, paving, new garden beds, pool fences and reticulation trenching all happen without much ceremony, and the retic cable is 200mm down and invisible. Half of these faults date from a landscaping job weeks or months earlier — the wire was nicked rather than cut, and it took a while to finish corroding through.

The rest come out of the valve box. Boxes flood, joints made with plastic screw connectors instead of gel-filled ones corrode, and the common wire has more joints in it than any other wire in the system because every valve taps into it.

The ban hides all of it. Nothing runs from 1 June to 31 August, so a wire that failed in July is not discovered until 1 September, by which time nobody connects it to the paving that went in over winter.

Is this a DIY job?

Yes. Everything below is 24V AC or purely mechanical, which is the part of a reticulation system a homeowner can safely work on.

Work out which of the two it is, for nothing

One — write down which stations are dead. Run every station from the controller and list them. The pattern is the diagnosis.

• Dead stations are consecutive on the controller's terminal strip — that points at the controller's output rather than the field wiring.
• Dead stations are scattered, or are the ones furthest from the controller — that is the common wire, broken somewhere out in the yard.

Two — check the water is not the problem. Go to one dead valve and turn its solenoid a quarter turn anti-clockwise. If water flows, that valve and its water supply are both fine and you have confirmed the fault is electrical. Do it up again afterwards.

Three — check the common terminal at the controller. Irrigation controllers keep the low-voltage station terminals in a separate compartment from the mains side, and the wiring compartment is the one that opens without tools. Look at the terminal marked C or COM. A common wire that has worked loose, or been pushed out when somebody added a station, will take out everything on it.

Stop here if the two compartments are not clearly separate on your controller, or if opening the wiring cover exposes anything mains-powered. That is an electrician's job and no sprinkler is worth it.

Fixing the common wire

You are looking for one break, and it is almost always in a valve box rather than in the middle of a run.

1. Open every valve box on the affected side of the property. Most systems have two or three.
2. Find the joints on the white common wire. You are looking for green powder on copper, a joint sitting in water, or a wire that comes apart when you tug it gently. Tug every one — a joint that looks fine and pulls apart is the answer.
3. Cut back to bright copper on both sides and rejoin with a gel-filled waterproof connector. Not a screw connector, not a twist-on cap, not electrical tape. Any of those will bring you back here in two seasons.
4. Leave enough slack that the joint sits up in the box rather than down in the water at the bottom of it.
5. Run the affected stations before you close the box.

If every joint in every box is sound, the break is in the buried run. That is where this stops being a good use of a Saturday — tracing a buried cable properly needs a tone generator and a wand, and a repairer with one will find it in twenty minutes. Get somebody with a locator onto it rather than digging exploratory trenches.

If it is the controller output

A dead output bank is not a repair, it is a replacement, and a controller is mains-powered. Do not open it. A replacement controller is a job for an electrician or a reticulation repairer, and it is worth asking for a quote on a new controller at the same time — an old one that has lost a bank is often close to losing another.

What it costs

Gel-filled connectors: a few dollars for a box, and the box will do every joint on the property. Buy the box.

Multicore irrigation cable, if a run has to be replaced: sold by the metre, cheap. We have not verified current Perth pricing, so ring a supplier rather than taking a number off the internet.

A cable locate: not something we have verified a rate for. It is a specific service — ask for it by name and ask what it costs before they come out.

A replacement controller: unverified, and it varies enormously with the number of stations and whether you want it on the phone. Get two quotes.

Common questions

Why did several sprinkler stations stop working at the same time?

Almost always the shared common wire. Every station runs off one common, usually white, so a single break kills everything downstream of it at once while the rest keep working.

How do I tell a common wire fault from a controller fault?

Look at which stations are dead. Consecutive stations on the terminal strip point at the controller output. Scattered stations, or the ones furthest away, point at the common wire out in the yard.

Can I repair reticulation wiring myself?

Yes. Field wiring is 24V AC and safe to handle. The controller itself is mains-powered and must not be opened — that is an electrician’s job.