Upkeep PlanTimed by soil temperature

Sprinkler blowout cost by number of zones

Pro quotes usually climb with zone count because each zone is cleared on its own. This page shows the published math behind that — compressor CFM from your zone flow, time per cycle, and fields for the prices your town actually charges.

What scales with zones

Colorado State University Extension is explicit: blow out one zone at a time, the same way the system runs in summer — trying to do more heats pipe and fittings. Each zone gets two short cycles, not one long one. Rain Bird's manufacturer guidance adds a two-minute ceiling per circuit per pass.

More zones means more cycles through the controller, more trips to connect and verify, and more backflow handling at the end — not a single flat fee hidden inside "winterization."

Compressed-air blowout: water shut off, air enters at the blowout port, each zone cleared in short cycles, backflow preventer handled separately Schematic side view. Water supply is shut off at the house. A compressor connects to the system blowout port — not through the backflow preventer. Air flows through the manifold and zone valve, pushing water out of the lateral line and sprinkler head. Working pressure 40 to 80 psi; maximum 80 psi for PVC and 50 psi for polyethylene. Two short cycles per zone, no more than two minutes per pass.Shutoffwater offBackflowno airZone valveCompressor40–80 psiportair pushes water outwater exits headTwo short cycles per zone≤ 2 min per pass · stop when dryvolume clears the line, not pressure
Each zone is blown separately — that is why quotes rise with zone count.
  • Compressor — connect at the blowout port; 40–80 psi working range
  • Backflow preventer — drain by hand; do not blow air through it
  • Each zone — two short cycles, not one long blow

Compressor size (CSU's formula)

Air volume clears the line, not headline pressure. CSU Extension: GPM ÷ 7.5 = CFM needed at the working pressure. Their worked example — a zone designed for 20 GPM at 30 psi — needs 2.67 CFM. Undersized compressors take longer and may leave water in low spots; oversized ones can pressurize too fast without a regulator.

If you do not have the as-built GPM, CSU says to add the nozzle GPM ratings on that zone from the manufacturer's site. Pressure limits still apply: 40–80 psi working range, 80 psi maximum for PVC, 50 psi for polyethylene.

Your system
Local prices (optional)

Published math

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Comparing quotes fairly

When two companies quote different totals, check whether both include the same scope: shutoff at the house, blowout port connection, every zone cycled twice, backflow winterized by hand (never blown through on a PVB or RP — CSU is explicit), and controller left powered for weekly minimum cycles.

CSU's closing line is qualitative but worth weighing: preparing the system in fall is much less costly and much less labor intensive than replacing burst fittings, valves, and backflow assemblies in spring. That is the repair bill you are buying insurance against — not a national average we can cite.

When DIY stops making sense

From the winterization guide's stop section: no volume compressor, pump on the system, reduced-pressure backflow, local code requiring a certified tester, or missing as-built drawings. A per-zone pro quote is routine; a split manifold in April is not.

Timing is not on this page — check whether the window is open in your region before you schedule either way.

Questions people actually ask

How much does sprinkler blowout cost per zone?

Most irrigation companies price by zone count or by tier (for example 1–4 zones flat, then per zone above that). We do not publish a national average — those SERPs are lead-gen marketplaces with proprietary job data. What scales linearly is the work: each zone is blown separately, usually twice, and CSU Extension says to blow one zone at a time, the same way you irrigate.

Is DIY blowout cheaper than hiring a pro?

A one-day compressor rental can cost less than a service visit, but CSU Extension warns that air volume (CFM) matters as much as pressure — an undersized shop compressor rides over the water instead of pushing it out, and freeze damage in spring costs more than the blowout saved. Compare your local rental quote against a written pro quote for the same number of zones.

What size compressor do I need?

CSU Extension: divide the zone's gallons per minute (GPM) by 7.5 to get the cubic feet per minute (CFM) the compressor must deliver. Their worked example is 20 GPM ÷ 7.5 = 2.66 CFM at 30 psi. If sprinkler heads stay up while air keeps flowing, the compressor is large enough.

How long does blowout take?

CSU recommends two short cycles per zone, not one long one. Rain Bird caps any single pass at two minutes per circuit. Budget at least two cycles × two minutes × your zone count before adding time to connect, walk the controller, and winterize the backflow assembly separately.

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