Pool pump won't auto prime on pool side

[Steve1944]

Hi guys,

I am new to this forum and joined TPF because of all the great posts and answers I saw.

I had my pool & spa built back in 1979 and it has run pretty well over the years. But just few weeks ago, the pump would come on but not circulate water from the pool to the spa. So pulled the WisperPro 1.5 HP pump and checked it out. Found that 5 of the 6 vanes in the impeller were blocked by some palm tree seeds.

So I removed the blockage thinking that had to be the problem but when I installed the pool pump motor, it still would not pull water from the pool. It would pull water from the spa. So I pulled the pump again and took it to Orange Park Pools to have Todd look at it since he had rebuilt it back in March. He said all looked fine but put in a new $14 seal just in case.

But when I installed the pool pump again, I had the same problem. It will pump water when the "In" valve is set to the spa, but not when set to the pool. If I do run the pump from spa water and then slowly move the "In" valve to the pool, it will finally pull water from the pool.

When the pump is pulling water, it is running strong and shows 25 psi on the filter canister. The pool water is not low and the strainers are both clean. Filters are clean and I do not see any leaks from the 2" pipes coming out of the ground to the "In" valve.

Any ideas?

Thanks, Steve

 

[AftonJeeper]

Is the spa water line above pump?

Since the pump checks out look at the o ring on the pump strainer basket. Try lubricating it or replacing it if necessary. Another issue could be a damaged valve, it may be completely open when switched to spa but when moved to pool there could be a blockage.

Is there any air in the pump basket once primed? Pool School - Suction Side Air Leaks

 

[Mayorb]

Check the lid and o-rings on your suction 3 way valve. It's not common, but a situation can arise where the valve hold tight in one position, but not the other. You also may want to blow out your suction line from the pump back to the skimmer. If large debris is jammed in a 90, it will prevent proper water flow to the pump.

 

[Steve1944]

The spa water line is below the input pipe to the pump by about 6". The pool water line is 12" below the spa water line.

I did lube the pump strainer basket cover o-ring and the o-ring looks like new. It seems air tight as makes quite a vacuum release noise when I undo the lid quickly after turning the pump off.

I have removed the "In" valve several times and lubed it too. It installs very tight and when the pump runs from the pool inlet, it runs strong and at 25 psi.

There are air bubbles in the pump basket when it is running strong from the pool inlet and same when running from the spa.

Thanks, Steve

 

[Steve1944]

I have checked the lid and o-rings plus lubed them. They are very tight and seem to be air-tight. Turning the "In" valve is hard as it is so tight unless just lubed.

I had used a small rubber bladder to send water from the "In" valve back to the pool skimmer. I also just put a hose in that line and water was coming out the pipe in the pool skimmer that seemed to be at hose pressure.

But I agree that there must be some blockage in the line from the pool skimmer to the pool pump basket or the pump would pull water and run fine. Maybe I can get hold of one of those burlap bladders and see if it will blow out any possible debris.

Do you know if water should stay in the "In" pipe from the pool after the pump shuts off? Should the vacuum hold the water unless there is a small air leak?

Thanks, Steve

 

[peirek]

Do you know if water should stay in the "In" pipe from the pool after the pump shuts off? Should the vacuum hold the water unless there is a small air leak?

Thanks, Steve

Yes it should hold the water. An air leak will let it drain back.

 

[Steve1944]

Okay Paul, that explains why it takes almost a minute for the pump to prime when it is turned on. But then, it runs strong now without me having to baby it along by running from the spa side first and then slowly move the valve to the pool side.

So it looks like my problem has been resolved as I just turned on the pool pump and it started pumping water from the pool in 45 seconds. My best guess is that there was some obstruction in the pool input pipe that through several days and hours of pumping, has cleared.

Thank you Paul & Mayorb for your kind help and thoughts. This is sure a great pool forum and now I don't feel so all alone when needing help on pool problems.

Steve

 

[peirek]

It sounds as if you cleared your blockage, what ever it was. Pump basket should give you some hints. However, it sounds like you still have a suction side air leak (in 45 seconds.....). You can decide yes or no to pursue correction.

Pool School - Suction Side Air Leaks