How often should you start up your sprinklers?

Why bother

Find winter-cracked lines before you rely on them. Standard upkeep. Dull and cheap, and a lot less dull than whatever it's quietly preventing.

What the job involves

1. Wait for the weather to stop trying to crack your pipes. Three to five nights above freezing and the soil thawed a few inches down, then walk the backflow preventer and any valves you can see, looking for splits the winter left behind.
2. Open the main supply valve slowly, a quarter turn at a time, and let the lines fill on their own. Charge dry pipes all at once and the pressure surge, called water hammer, slams down the line and splits fittings.
3. Run the zones one at a time. Let each flush its debris, then watch for geysers, dry patches, leaks, and heads sat crooked or clogged. Straighten and clean them as you go.
4. Check the pressure sits in the 40 to 65 psi range, then reprogram the controller for the season and swap the backup battery while you remember it exists.

Do it yourself, or pay someone?

Yourself, if you can find the backflow preventer and the main valve and you open things slowly. The parts are cheap and the steps are short. Pay a pro ($60-$125 for a typical home, near $90 average, about $8-$17 per extra zone) if the system's big and multi-zone or you'd rather someone catch the winter damage; a certified backflow test runs $75-$150 on top where your area demands one.

What skipping it costs

$150-$500 is the usual bill for the burst or frozen line a careful startup catches before any water goes in. Charge the system fast, or charge it over a crack you never spotted, and the surge does the rest. Separately, the EPA's WaterSense puts a season of undetected leaks and broken heads at up to around $280 of water poured into the ground for nothing. A slow open and one walk of the zones costs an afternoon.

Signs it's overdue

• Brown or wilting patches in the beds and lawn while the neighbors' systems are running, which means a zone or a head isn't getting water where it's meant to.
• A soggy spot that never dries, a sinkhole, or a water bill that's gone up for no reason you can name, all of it pointing at an underground leak or a broken line running unseen.
• Heads that won't pop up, spray sideways, mist, or geyser, plus low pressure across the zones, the marks of clogs, freeze damage, or a cracked backflow preventer.

When to start thinking about it

A few days' warning does it. Grumpty grumbles 3 days out, then leaves you alone. Mark it done and Grumpty sets the next one, every 12 months, so you can go back to forgetting it exists.

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