Winterize Inground Pool without Draining Water

Winterize Inground Pool without draining: To close an Inground Pool without lowering the water level, (particularly those with a vinyl liner) isn't as tough as it might seem. For the first couple of years, we had a professional installer handle it, costing us upwards of $1500 for both the closing and opening services here in the midwestern USA. Now, we handle the process of winterizing it ourselves, saving over 80% of the cost after the initial equipment investment.

In this guide, I share the steps I use to winterize our vinyl liner inground pool, along with the key products I use. Note, those are Amazon Affiliate links and this site can benefit from a small kickback from any item purchased there during your visit, at no additional cost; actually, in most cases, an even greater savings is passed on to you.

How to Close an Inground Pool for Winter

Before you begin to close an inground pool without lowering the water level, you'll need to invest in a high-quality pool line blower. While some people try using a Shop Vacuum, I found it doesn’t provide enough pressure. Fortunately, the same commercial-grade Cyclone Pool Line Blower that our installer uses is available for purchase and has been a great investment for us.

You'll also want a pool hose for the blower. I recommend the JED Pool Tools 60-345-06 Hose, which comes in various lengths. I found the 6-foot version to be plenty long for most setups.

For winterizing the pool skimmer, I use the Gizzmo Pool Skimmer Plug with Blowout. It compresses if your skimmer fills with water and freezes, preventing the skimmer housing from cracking due to freeze expansion. I add an extra layer of protection by covering the skimmer face with a Wide Foam Skimmer Face Cover.

Finally, remember to use Winterizing Plugs to seal the pool nozzles and jets, preventing water from entering the lines during the winter months.

Steps to Winterize Inground Pool with a Vinyl Liner

Since we have an inground vinyl liner pool with built in vinyl over steps, we were advised to keep the water level at its normal height, above the steps, to prevent the liner from shrinking in freezing temperatures. The steps we use to winterize inground pools with a vinyl liner without draining or lowering water level are as follows:

1. Turn off the breaker power to the pump and any other accessories.
   • Make sure to check all related circuits to prevent any electrical hazards.
     
2. Plug all the nozzles:
   • Tighten them by hand until the o-ring is barely seated, then turn them another 1/4 turn to seal. This creates a secure hand-tight seal without overtightening.
     
3. Remove the skimmer trim ring from around the skimmer face and plug the skimmer with the foam skimmer plug.
   
4. Remove the black plug from the Gizzmo and insert the assembly into the skimmer return line hole.
   
5. Remove the drain plug from the water filter and allow the water to drain from the filter and lines.
   
6. Remove the blowout plugs from the nozzle lines.
   • These are usually located on the deck, directly above the last nozzle for each run.
     
7. Close the return valve for the skimmer and bottom pool return lines, and then,
   
   Open the valve for the nozzles/jets.
8. Insert the Cyclone Pool Line Blower hose into the pool filter plug opening, turn on the Cyclone, and hold the hose in place.
   • You'll see water spray from the nozzle blowout openings. Keep the blower running until the water becomes a fine mist, then turn off the blower and move to the next step.
     
     
9. Close the valve for the supply nozzles/jets and then,
   
   Open the valve for the return skimmer line only.
   
10. Run the Cyclone pool blower again until only a fine mist comes from the Gizzmo hole at the skimmer. Then turn off the Cyclone.
    
11. Using a funnel, pour a couple of gallons of Pool and Spa Winterizing Antifreeze into the Gizzmo's top opening, and into the Blowout plug openings for the nozzle lines.
12. Plug the Gizzmo with the black plug you previously removed and replace the blowout plugs for the nozzle lines.
13. Turn the turn the valve from skimmer to the pool bottom return drains only.
    
14. Run the Cyclone again.
    • You should see aggressive bubbling from the bottom drains. Let this run for a few minutes, then move the valve to the Skimmer while the Cyclone is still running, and then turn off the Cyclone.
      
    • This purges the bottom return lines and vacuum locks the air in the lines (like capping a straw). Leave this valve closed through the winter. I also remove the handle from the valve assembly once finished to ensure it stays that way.
15. Drain the pump chamber.
    
16. If there are caps near the pump for the nozzle feed lines, remove them and pour a couple of gallons of antifreeze into them, then replace the caps.
    
17. Double check that all the water is drained from the system. Once you're sure, you're finished.

And that's all there is to winterizing inground pools or to close an inground pool with a vinyl liner using a pool line blower without needing to lower the water level or drain it. Each year we do this ourselves, we are saving money that we can then put back into pool chemicals and later down the road, replacement parts. If you're looking to tackle this yourself, I think small investment upfront in equipment and closing material costs are well worth the long term savings. The first year alone, pays for the equipment more than 4 times over in what was saved by paying the installer to close the pool for us.

Is your pool chlorine level always low even after you've shocked your pool? Does the chlorine not register the next day? If so, you might want to check out my post about pool shock not raising chlorine level. This is a common issue newer pool owners encounter.