Submersible Pump Airlock After Power Outage: Priming Fix

The Problem: Airlock

Power cut → pump stops → water drains back → air fills volute/impeller chamber. On restart, pump spins but moves air, not water. Common in submersibles with vertical discharge.

Fix: Submerge & Burp

You did it right: remove, submerge fully, shake gently, reinstall. Water displaces air. Flow returns as air purges.

Prevention & Faster Restart

1. Check valve on discharge (prevents back-drain).
2. Drill 1/8" vent hole in discharge pipe just above pump — lets air escape on startup.
3. Pour water down intake before power-on (if accessible).
4. Clean filter box — clogged media mimics airlock symptoms.

When to Worry

If pump hums but no flow after 5 min submerged → impeller jammed or motor failed. Test in bucket: if works there, it's plumbing/airlock. If not, replace.