Pool Pump Blowing Bubbles?
If you are noticing that your pool pump is blowing bubbles out of the return lines in the pool, you have a leak someplace in your equipment. There are two sides to the water circulation system in a swimming pool. There is the suction side which includes all of the equipment and piping ahead of the pump, and then there is the pressure side which includes all of the equipment and piping after the pump. Another way to look at this is to remember that the pump is literally sucking water out of the pool and blowing the water back into the pool thus completing the circulation. If you were to have a leak on the pressure side after the pump, you would see a gush of water or the very least a drip at the place of the leak. This is very similar to a leak in the water pipes in your home. You will know it right away if it happens.
If you have a leak on the suction side ahead of the pump, the leak is not so apparent. There are many places for suction leaks to occur such as Jandy type valves in the piping or perhaps the pool has shifted in the ground slightly and cracked the underground PVC piping below the skimmer box. One of the most common places for a suction leak is the big o-ring under the pump lid. This is due to the lid being opened often for cleaning. The o-ring becomes dry and will split or crack thus allowing for air to be sucked directly into the pump and is the cause for the pool pump blowing bubbles back into the pool.
Another often seen symptom is the pool owner will over-tighten the lid to the point of deforming the o-ring and causing a suction leak. This o-ring needs to be inspected each time you open the pump lid for cleaning. It is always a good idea for a pool owner to lubricate the o-ring using a lubricant specifically designed for this purpose. One important note is to NOT use an o-ring lubricant on the plastic lid threads. It will eventually get too sticky and make the lid difficult to remove.
Use an O-ring lubricant
On my pool route I use Hayward Jacks Multilube on any o-ring I see. I go through a lot of this lubricant as there are o-rings all throughout a typical pool system and it is indispensable for anyone who maintains pool equipment. Do not use petroleum jelly as a lubricant as this will damage those expensive o rings rather quickly. Another reason for the pool pump blowing bubbles is over tightening the lid and deforming the o-ring. You don’t need to tighten the lid on a pool pump excessively. Just a snug hand tighten is all that is necessary.
One last tip for trying to find a suction side leak is to mix up some dish soap in a spray bottle and spray around the valves and any other equipment ahead of the pump. Then watch for soapy bubbles in the pump and this will often pinpoint a leak that is otherwise impossible to see. Just spray one area at a time till you see the bubbles.
Keep your o-rings lubricated and you will enjoy a leak free season!