Losing pressure when vacuuming pool

[vbcruiser]

My pool system is about two and half years old. It has worked without a problem. Now the system looses pressure when I vacuum.

This is a Hayward sand filter type system with a VERI FLOW XL Valve.

1. The system pumps normal with the pressure between 15 and 17.

2. When I turn the in line valve to the vacuum position, the pressure stays between 15 and 17.

3. When I insert the vacuum hose i have suction for about 30 seconds, then the suction slowly gets weaker with a small amount of air coming through the jets into the pool, to no suction in about 10 seconds with air returning to the skimmer pushing the vacuum hose out of it's seat.

4. I tried a different hose and the same problem exists.

5. I checked the in line basket filter seal, it looks fine and I made sure it is seated properly.

I was hoping someone could offer some possible causes and solutions.

 

[launboy]

Do you have a lot of air in the pump basket when the suction drops? Make sure you prime the vacuum hose before connecting it to the skimmer. Just hold one end in front of the return until no more air bubble out of the other end. Then keep both ends of the hose underwater until it is connected to the skimmer. Also, if you have a swivel cuff on one end of the hose make sure it is at the vacuum head end, not the skimmer end. If it's at the skimmer end it can let water in causing the pump to lose prime.

HTH,
Adam

 

[vbcruiser]

Yes we have done that for a couple of years and it works perfect. Must be something else. Thanks for the info though.

 

[waste]

Hi and welcome to TFP!!

Sounds like a suction side air leak I saw Adam's post and figured he was right, but you say it's not that.

Perhaps there is a pump lid gasket issue that only truly shows when the extra pressure from the vacuum is occurring.