06 Leak Test

The plumbing is done. Before any electronics get involved, you fill the bucket, direct-wire the pump, and walk each zone under power. Water plus a not-yet-ready Pi is how you fry hardware; water plus tested plumbing plus a 12V brick is just a test rig.

Why test before electronics

This is the most important step on the page. Don’t connect the Pi yet. The reason isn’t fragility — it’s diagnosis. When everything is wired together and a zone fails, you’re debugging six things at once: pump, valve, push-fit, emitter, GPIO, and code. Test the plumbing in isolation and the only failure modes left are mechanical. Every barbed connection, every push-fit, every emitter, and the float switch’s open/closed states all get exercised here, with nothing else to blame.

If you wired the float switch with the leads pointing up out of the bucket lid and the float drops to the bottom of the cord whenever you tilt it sideways, the wiring is fine — the float just needs water under it to lift. Set the float assembly aside until step 1 puts water in the bucket.

Step 1 — Fill the reservoir

Fill the 5-gallon bucket with water. Snap the lid on. Confirm the float switch is floating — the float being UP closes the circuit, and UP means water is present. If the float sits at the bottom of its cord with the bucket full, the float assembly is upside-down; pull it out, flip it, and re-thread.

Step 2 — Direct-wire the pump

Using the barrel jack pigtail and the 12V power supply:

Connect the 12V adapter to the barrel jack pigtail.
Touch the pigtail’s screw terminals directly to the pump’s power leads (red to red, black to black). The pump should start immediately.
Water flows into the 6-way T manifold and stops at every closed solenoid. Since all valves are normally closed and unpowered, no water should pass through them. Confirm this. If water visibly leaks past a closed solenoid, that valve is defective — replace it. Cheap solenoids occasionally fail closed-but-not-water-tight; rare, but it happens.

If the pump doesn’t start at all, check the polarity at the screw terminals (some 12V supplies are reversed-tip) and confirm the float is floating.

Step 3 — Walk each zone

For each zone, one at a time:

Touch 12V directly to that zone’s solenoid leads (red to +, black to −). The valve clicks open audibly.
With the pump still running and one valve open, water flows through that zone’s branch line and drips from every emitter on that zone.
Walk the line. Every fitting, every barb, every emitter. Look for:
- Drips at fittings → tighten the hose clamp or re-seat the tubing
- Tubing popping off a barb → dip in hot water, re-push, add a hose clamp
- Emitters not dripping → clogged or closed; unscrew the top, clear it, reassemble
- Emitters spraying wildly → adjustment screw is wide-open; turn it down
Confirm the OTHER zones stay dry while this one is open.
Disconnect that zone’s 12V. Water should stop within 2 seconds. Move to the next zone.

Most leaks here are push-fit fittings. If a solenoid leaks at the inlet or outlet, the tube wasn’t pushed in far enough. Fix: push the blue collet IN with one hand, pull the tube straight out with the other, re-cut the end clean and square (sharp utility knife or proper tubing cutter — kitchen scissors squash the tube oval and won’t seal), then push the tube back in HARD until it physically refuses to go further. Tug back lightly to set the teeth. The full diagnostic — all four ranked causes, the “what NOT to do” list, and why the blue ring spins freely — lives on page 05 — Plumbing.

I had three leaks on my first run — all push-fits, all fixed by the procedure on page 05.

Step 4 — Check flow balance

With your largest zone open (the one with the most emitters) and the pump running, watch whether the last few emitters on that zone get noticeably less water than the first few. If they do:

Open the last emitters wider (turn counterclockwise)
Or close the first emitters down (turn clockwise)

The goal is roughly even drip rate across all the emitters in a single zone. Different zones can have different rates — that’s fine, and expected if one zone has 4 emitters and another has 12.

Step 5 — Float-switch dry-run

Lower the bucket water below the float. You can siphon some out, or just let the test runs from steps 2–4 drop the level naturally. The pump should stop. Confirm it. Refill the bucket and confirm the pump can restart.

This is the hardware safety cutoff. Even if the Pi software is fine, when the bucket runs dry, the float drops and the pump physically loses power on the 12V positive line. Page 12 covers software-level reservoir monitoring; this float-switch test is the belt-and-suspenders hardware version, and it runs without code.

Step 6 — Fix every leak

Every leak you see now becomes a puddle in 8 hours and an angry downstairs neighbor in 24. Fix every drip before moving on.

Push-fit leaks: see step 3’s pitfall callout, or the full diagnostic on page 05.
Barb leaks: dip the tube end in hot water, re-seat onto the barb, add a hose clamp.
Emitter leaks: re-seat the stake into the tubing, or replace the emitter (they’re cheap).
Threaded leaks (rare, only at the pump output): a wrap of Teflon tape on the threads.

A drip you can fix in 30 seconds now is a drip you can’t fix from the office at lunchtime in August.

Sign-off checklist

Before you move on to page 07 (or page 08 for advanced), verify all of:

Pump starts when 12V is applied directly. Pump stops when 12V is removed.
Every solenoid clicks open when 12V is applied to its leads.
Every solenoid stops flow within 2 seconds when 12V is removed.
Closed solenoids hold against pump pressure (no water passes when the valve is unpowered).
Every zone has working flow at every emitter.
Flow is roughly even across emitters within each zone (any imbalance under ~30%).
Float switch cuts pump power when the water level drops below it.
No leaks at any fitting, anywhere, after running each zone for at least 60 seconds.

If all 8 are checked, the plumbing is done. Disconnect the 12V supply (you’ll re-wire it through the relay on page 08). Move to page 07 (soldering, if you’re going that path) or page 08 (electronics, for advanced builders going direct-wire).

With the plumbing tested and signed off, the next page is either soldering the relay screw terminals to a perfboard (page 07, recommended for first-time builders) or wiring straight through to the relay (page 08, advanced).