Most years the safe window for a spring startup in Spokane runs from about April 15 to May 15, after the last hard freeze. If snow is still on the ground or overnight lows are dipping below 28 degrees, wait. Open the main valve slowly, over 30 to 60 seconds, to avoid water hammer.
Then run each zone for two or three minutes and walk it: look for geysers, water bubbling up around a head, dry spots and heads spraying the driveway. If you see water where it shouldn’t be, shut the system down and call.
Step-by-step guide: Spring sprinkler startup in Spokane.
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