Air leak coming from AFTER the pump??

[Darron]

I've been trying to determine where air is getting into my main filter pump. It starts as a tiny bubble in the pump basket and spreads within a few minutes to take up the entire clear lid area.

By chance, we got a ton of rain today so I had to pump to Waste. When I moved the filter valve to Waste, I had a perfect seal in the pump basket....no air! And I had to run it for several minutes due to the amount of rain.

I've been told to look for the air leak from BEFORE the pump basket such as checking the O-rings on the automatic and main drain valves. Any idea why changing something AFTER the pump would stop the air leak?

I switched the valve back to Filter and the air leak is back again.

Many thanks,
Darron

 

[duraleigh]

Any idea why changing something AFTER the pump would stop the air leak?

Sure. But tell us this first......when you switched to "waste", did you psi on the filter go up or down from it's normal "filter" setting?

 

[Darron]

Sure. But tell us this first......when you switched to "waste", did you psi on the filter go up or down from it's normal "filter" setting?

To be honest, I never looked at the PSI gauge when I initially did this. So I just went back and repeated the steps again. The PSI gauge stayed on 0 when I switched to Waste. This is what you would expect since the Waste valve is before the filter and diverts the water to the Waste pipe, correct?

The result was the same as the first time....no air bubbles in the pump basket.

 

[duraleigh]

So then your normal filter psi is probably around 10-14 or so.....the exact reading doesn't matter.

In "waste" position there is little resistance on the pressure side and the water is allowed to flow more freely. In filter position, the resistance on the pressure side is much higher, causing the suction side to "pull harder" to overcome that resistance.

As the suction side pulls harder, it is able to crack open your leak and suck in air. Put back in "waste" mode, there is again less resistance and the leak can stay sealed.

While it can be elsewhere, the pump basket lid (a bad o-ring) is the most likely culprit in that scenario. Please don't overtighten that lid......it should seal perfectly with hand tightening

 

[jimmythegreek]

Duraleigh nailed it with a thorough explanation. Well said my friend

 

[Darron]

So then your normal filter psi is probably around 10-14 or so.....the exact reading doesn't matter.

In "waste" position there is little resistance on the pressure side and the water is allowed to flow more freely. In filter position, the resistance on the pressure side is much higher, causing the suction side to "pull harder" to overcome that resistance.

As the suction side pulls harder, it is able to crack open your leak and suck in air. Put back in "waste" mode, there is again less resistance and the leak can stay sealed.

While it can be elsewhere, the pump basket lid (a bad o-ring) is the most likely culprit in that scenario. Please don't overtighten that lid......it should seal perfectly with hand tightening

Got it. That makes sense. After after reading a few of the other "air leak" threads, I think I found the culprit. There is a small water leak in the junction right above the pump (circled in green below). You can see the water dripping down the side of the pump casing. From one of the other threads, it sounds like this leak can also pull air into the pump.

Do you agree? If so, is this an "easy fix" for a novice, or do I need to call a plumber?

Thanks again.

 

[jimmythegreek]

At that spot if water is leaking out it's a pressure leak and would not let air in if water is coming out. I would check the other fitting into the pump right before that one too. You could try food wrap to seal different spots or spray water from hose patiently on each fitting from ground to the intake. The pump lid is lubed and tight?

 

[Darron]

At that spot if water is leaking out it's a pressure leak and would not let air in if water is coming out. I would check the other fitting into the pump right before that one too. You could try food wrap to seal different spots or spray water from hose patiently on each fitting from ground to the intake. The pump lid is lubed and tight?

The pump lid is closed tightly, but I don't know when the last time it was lubed (I just bought the house back in September and recently took over from the pool company). I'll start with a new o-ring and lube to see if that's the issue. If not, I'll check each fitting as you recommended.

How much of a concern is the water leak right above the pump? It doesn't seem to be causing any issues that I can tell....not even enough water coming out to puddle at the base of the pump.

 

[mknauss]

A leak on the pressure side can allow air in to the system when the pump is OFF. So it is not contributing to your issue but can be allowing your system to drain when the pump is shut down. The the pump has to do a full prime the next time it starts.

 

[Darron]

A leak on the pressure side can allow air in to the system when the pump is OFF. So it is not contributing to your issue but can be allowing your system to drain when the pump is shut down. The the pump has to do a full prime the next time it starts.

Ahh...thanks, Marty. That makes a lot of sense. I've noticed the pump is having a harder time priming....I assumed (incorrectly) it was related to the air leak in the pump basket. But based on your explanation, it's probably the leak on the pressure side.

I think I already know the answer, but being a relative novice, should I even mess with trying to fix the pressure-side leak, or just call a plumber?

 

[mknauss]

It is a union. It may have an oring that needs lubed or replaced. Or it may just need to be tightened.