Air entering a swimming pool from its water return jets is a common problem that has bedeviled many pool owners. In most cases of water being dispersed into pools through their water returns, an air leak emanating somewhere in the pump system is a typical cause. Locating the source of an air leak in a swimming pool's pump system takes a bit of detective work. Preventing air from getting into a swimming pool through its water returns also requires consistent pool preventive maintenance.
Air emanating from swimming pool water return jets indicates suction side leaks in a pool's filter pump system. Pool filter pumps are designed to suck in pool water on the suction side and push out filtered pool water on the return side. A pool pump suction side leak means that air is being sucked into the pool-to-pump water lines, usually near the pump itself. In pool pump suction side leaks, air and filtered water are intermingled and returned back to the pool.
Suction Side Repair
When you see air coming from your pool's water return jets, look first at the pool's suction side pump fittings. Pool pump suction side fittings are known to swell, thereby causing them to lose their airtight characteristics. A simple solution to non-airtight pool pump suction side fittings is to reapply fresh seal tape over the male adapter ends of all suction side pipes. After re-taping all pool pump suction side fittings, reinsert and then tighten them down to eliminate any suction side air leaks.
Another part of the pool's pump that can allow air to get into water return lines is the pool pump lid's seal, rubber O-ring or gasket. The pool pump lid's O-ring will wear out over time and lose its airtight seal, allowing air to enter the pool pump from the top. Any air entering the pool pump from its lid will eventually make its way back out of the system through the pool's water return jets.
Occasionally a pool pump's drain plug will work its way loose and become less than airtight. A loose pool pump drain plug will allow outside air into the pump where it will then be sent on to the pool's water return jets. Inspect your pool pump's drain plug regularly, retightening it as needed. If your pool pump's drain plug is still loose after retightening, unscrew it, re-tape it using fresh pipe tape and tighten it back down to create an airtight seal.
Periodically check your swimming pool's wall fittings to ensure they're tight, In addition, carefully examine your swimming pool's water piping for splits or leaks. Any inadvertent opening at any point in a swimming pool's pump system will allow air to be drawn in and then put into the pool. Address a pool pump's air leaks immediately because large ones can cause the pump to lose its ability to draw water, leading to it burning out.