Know Your Pool: Pump Drain Plugs
The Two Little Plastic Things You Lose Every Winter (And Why Forgetting Them Costs $1,500+)
If you have a pool in McKinney, Frisco, Prosper, Allen, Plano, or Celina, there are two tiny plastic plugs on your circulation pump that you have probably never noticed… until the one night they could have saved you thousands.
They’re called pump drain plugs (sometimes winterizing plugs or priming plugs). They screw into the bottom or front of the pump basket housing and their only job is to let water completely drain out when you need it to.
Leave them in (or lose them and never put them back) before a hard freeze, and trapped water turns to ice, expands, and splits your pump housing wide open.
We’ve been fixing pools here since May 2018, and every February the most common freeze-damage call we get is a cracked pump — almost always because those two little plugs were either forgotten or missing.
Here’s everything you need to know so your pump survives another Texas winter.
What Pump Drain Plugs Actually Do
Your circulation pump is basically a big plastic bowl full of water. When the pump is off, gravity keeps that bowl filled right up to the pool water level.
When temperatures drop below freezing and the water sits still, it expands about 9 % as it freezes. That expansion has nowhere to go except to crack the pump housing, blow the lid O-ring, or split the volute (the front half of the pump).
The drain plugs are the emergency escape hatch. Unscrew them → water drains completely out of the pump basket → nothing left to freeze → pump stays safe even at 15 °F.
Every major brand has them in roughly the same spot:
- Pentair (IntelliFlo, WhisperFlo, SuperFlo, etc.) → two clear/white plugs on the lower front of the basket
- Hayward (TriStar, Super Pump, MaxFlo) → two plugs on the bottom or lower side
- Jandy (Stealth, PlusHP, FloPro) → usually two on the front face or bottom
Not sure where yours are? Snap a quick photo of your pump and text it to us — we’ll circle them for you in two minutes.
Why These Plugs Disappear More Often Than Socks in the Dryer
They’re small, slippery when wet, and usually clear or white — the trifecta of “gone forever.”
The most common ways they vanish:
- Taken out to drain the pump and set down “somewhere safe” (i.e., the grass)
- Fall into the pump basket and get tossed with the leaves
- Kids think they’re toys
- Go through the washing machine in a pocket
- The dog carries them off
We keep a coffee can full of spares on every truck because we hand them out constantly in fall and spring.
Pro move: The instant you remove them, drop them straight into the pump basket or skimmer basket. That way they’re impossible to lose and are right there waiting when you reassemble in March.
What Actually Happens When Water Gets Trapped
Water stays in the pump basket → turns to ice → expands → plastic has to give somewhere.
The result is almost always a cracked pump housing or volute. That’s not a $200 fix — it’s a new pump (or at minimum a new wet end) plus labor. Even on older single-speed pumps that’s $800–$1,200. On today’s variable-speed pumps it’s $1,800–$2,800 easy.
We see it every single year, and it’s 100 % preventable.
How to Check and Use Your Drain Plugs Right Now
Takes 30 seconds:
- Walk to your pump (the big thing with the clear lid on top).
- Look at the very bottom or lower front — you should see two small knurled knobs or slotted plugs.
- They should be finger-tight and have intact O-rings.
- If either is missing, cracked, or the O-ring is shredded, replace it now while the weather is nice.
When a hard freeze is forecast:
- Flip the breaker off
- Unscrew both plugs (drop them in the basket!)
- Let the water drain completely onto the pad
- Leave them out until the cold snap passes
- Screw them back in before turning the pump on again
If we handle your professional winterization, we do this (and every other drain point) automatically.
The “I Have No Idea Where Mine Went” Fix
Replacements are cheap, universal, and easy.
We stock every common size on the trucks and are happy to drop off a pair (or four) next time we’re in your neighborhood.
DIY Assist members — we check all drain plugs (pump, filter, heater, everything) and replace missing or damaged ones at no extra charge during your visits.
Bonus Tips to Never Lose Them Again
- Buy four spares today and keep them in a labeled Ziploc taped inside your equipment area
- Wrap bright tape or a neon zip-tie “flag” around them
- Sharpie “DRAIN PLUGS GO HERE →” with an arrow on the inside of your pump lid
- Take a phone photo the day you remove them so you remember exactly where they live
- Ask us to sticker the spots when we’re out — we do it standard for every DIY Assist customer
What Now?
Your pump drain plugs are two of the smallest and cheapest parts on your pool… and forgetting about them is one of the most expensive mistakes you can make in winter.
Go find them today. Make sure they’re there, intact, and ready.
If they’re AWOL or damaged, text or call us at 469-352-9191 today!
For DIY Assist members — you’re already covered, so just schedule that winter-ready check-up and we’ll handle the rest.
Don’t let two missing pieces of plastic turn your pump into an ice grenade.
Stay warm and keep that water draining,
— Your local Pool Scouts of McKinney & Greater Dallas crew
Proudly keeping Collin County pools alive since May 2018
P.S. Seriously — check those plugs this weekend. You’ll thank yourself in February.