Winterize the pool
Annual · typically September · weather can move it up
Why it matters
Closing a pool isn't about the water in the bowl — it's about the water hiding in the plumbing. With around 60–120 freeze days a year, every line under your deck will spend real time below 32°F. Water in those lines freezes, expands about 9%, and pipes lose that fight every single time.
The bowl itself stays full all winter on purpose: the water weight and the cover protect the shell. It's the skimmer, returns, and equipment that have to be dry.
What skipping it costs
$1,500–$10,000
Water left in the lines freezes, expands, and cracks pipes under your deck — damage you discover in May, not December. Cracked underground plumbing runs $1,500 to $10,000 with concrete cutting. The blowout that prevents it takes an afternoon. This is the irrigation-blowout story with three more zeros available.
Two ways to get it done
Do it yourself
You'll need: Air compressor or shop vac (blowout-capable), Winter plugs and gizmos, Cover and water tubes/anchors, Winterizing chemical kit, Non-toxic pool antifreeze for lines (belt-and-suspenders).
Real talk first: this is the most technical task in your year. If you've never done a blowout, watch it done once before trusting your own.
- Balance the water and add the winterizing kit a few days before closing — while the pump still circulates.
- Drop the water level below the skimmer mouth (or per your cover type's spec). Do not drain the pool.
- Drain the pump, filter, heater, and any salt cell — pull the drain plugs and store them in the pump basket where spring-you will find them.
- The blowout: push air through the skimmer, return, and main drain lines until they blow steady bubbles, then plug each one under pressure. The main drain gets blown until it bubbles, then valved off — it airlocks and stays dry.
- Antifreeze in the lines is cheap insurance on top of a good blowout, not a substitute for one.
- Cover on, tight, with drainage or a pump plan for the top — 400 pounds of November rainwater has torn plenty of covers.
Watch for: any line that won't blow bubbles. That's a blockage or a break, and it needs finding now, not in May.
Hire it out
$250–$500National fair range — local labor moves this number.
A full professional closing runs $250–$500 — blowout, plugs, equipment drain-down, chemicals, cover. It's some of the best money in your whole house year, because the failure mode it prevents is buried under concrete.
Make sure you're buying the real service: the question to ask is number one on the list — every line blown and plugged, not just the equipment pad drained. And if anyone suggests fully draining the pool "to be safe," that's your cue to call someone else; empty shells pop out of the ground in wet winters, and that's not a repair, that's a rebuild.
Ask the tech
- Are you blowing out every line — skimmer, returns, main drain — and plugging them, or just draining the equipment?
- What happens if a line cracks over winter anyway — do you stand behind the closing?
- Are you winterizing the heater and salt cell too, or is that on me?
Red flags you're being upsold
- A 'closing' that's just chemicals and a cover, with no line blowout, in a freeze climate. That's $300 for the easy half of the job.
- Pushing a full drain-down of the pool. An empty shell in winter can heave or crack from groundwater pressure — pools winter better full.
- New-cover hard sell every fall. Covers last 8–12 years; patches are a thing.
Second opinion time: Any spring 'freeze damage' repair over $2,500 — especially underground line replacement, which gets quoted by guesswork unless someone actually pressure-tested.
The call
Hire this one. The line blowout is the whole game, and doing it wrong looks exactly like doing it right until spring. A proper closing costs less than one foot of trenched pipe.