Domakihub Pool pump won't prime? How to fix it
If the pump runs but no water moves — or it keeps losing prime — it's almost always air getting in on the suction side. Here's how to find and fix it.
Reviewed by Domakihub pool pros · 2026-06-23 · 5 min read
"Priming" just means filling the pump with water so it can pull more through. When a pump won't hold prime, air is leaking into the suction line and breaking the vacuum. The video above shows the quick prime; the checklist below walks through the usual culprits, in the order worth checking.
How to tell it's an air leak
Look at the pump's clear lid while it runs: lots of swirling bubbles and a low, foamy water level mean air is getting in before the pump.
Air leaks are almost always on the suction side — between the pool and the pump — because that side is under vacuum. The pressure side (after the pump) leaks water, not air.
Get your pump to prime in 5 steps
- 1
Fill the pump basket with water
Turn the pump off, open the lid and fill the basket housing with a hose. This gives the pump water to grab so it can start the siphon.
- 2
Reseat the lid and its O-ring
The pump lid O-ring is the number-one air leak. Clean it, smear a little silicone lubricant on it, and hand-tighten the lid firmly — no tools.
- 3
Empty the baskets
Clear the pump basket and the skimmer basket. A clogged basket starves the pump and makes it lose prime.
- 4
Check the water level
If the water is below the middle of the skimmer, it sucks air. Top the pool up to the right level and try again.
- 5
Hunt the suction leaks
With the pump running, work along the suction plumbing — unions, valves, the drain plug — and look for the bubbles to stop when you seal a fitting. Tighten or re-tape the culprit.
Rather have a pro handle it?
Get a vetted pool pro in your city — one number, booked in EN/EL/DE.
FAQ
- Why does my pump keep losing prime overnight?
- A small suction-side air leak lets the water drain back when the pump stops. Check the lid O-ring, the drain plugs and the union fittings first.
- There are bubbles coming out of the return jets — what does that mean?
- Air is being pulled in on the suction side and pushed through the system. It's the same air-leak problem, not a return issue.
- The pump runs but moves no water at all — is it broken?
- Usually not. It's lost prime (no water to pull) or has a blockage or big air leak. Prime it and check the baskets before assuming the motor or impeller has failed.