Pump runs dry for 1 hour before pumping water

[nabin]

I have filter and pump 5 ft above the surface of the pool (I bought the house with this already that way). It is a 1.5 HP Century motor. The pump runs dry for 1 hour before pumping water through the filter. Every time I shut the pump off, restarting becomes a big chore.

Please provide your advise.

 

[zea3]

Could you post a picture of your pool and your plumbing layout? An inground pool pump should not have that much difficulty catching prime and an hour is much too long a time to run "dry". Does your pool have an attached spa?

 

[RMcGirr83]

Don't believe it should run completely dry to begin with? That kind of leans toward a suction side leak somewhere I would imagine.

 

[blazer58]

That sounds to long to me also.
My pump is app 5/6 feet above pool, 40 feet away and takes 7 mins or so to prime

 

[nabin]

That sounds to long to me also.
My pump is app 5/6 feet above pool, 40 feet away and takes 7 mins or so to prime

Thank you. And when it is priming - is it normal for it to run dry (asking because my knowledge and experience on pool is not good)

 

[blazer58]

It starts out dry, for a min or so, then water slowly starts getting pumped.
It never runs dry for longer than an min or two

 

[jimmythegreek]

The pool pump should stay full of water for the most part. In a sealed pipe system submerged, intake and return points cannot leak back without air getting in somewhere. You have a leak, start by checking the obvious pump lid and plugs theres a link somewhere on here of steps you can do

 

[Jimrahbe]

N,

A pump should prime in seconds not hours...

When you shut the pump off, does all the water in the pump basket drain back out of the basket?

It should not, it should stay in the pump, if it drains back it indicates air is getting into the system at, or after, the pump.

Do you hear air rushing into the system when the pump is off?

When is the last time you inspected and lubed the O-Ring under the pump lid?

Thanks,

Jim R.

 

[blazer58]

water stays in my pump basket when it shuts off, but when the pump starts to prime, it gets sucked out, the it takes a min to start pulling water again.
I assume this is normal, as my setup has always done this

 

[jimmythegreek]

Do you have a check valve before your pump? If you do it sounds like you may have a small leak from pool to the check valve. If pump is full it should have water the whole prime cycle, it shouldn't pull it dry then have water after

 

[blazer58]

Do you have a check valve before your pump? If you do it sounds like you may have a small leak from pool to the check valve. If pump is full it should have water the whole prime cycle, it shouldn't pull it dry then have water after

If that was for me, I have no check valve.
I am going to recheck my pump today to see how it primes, been awhile since I really looked at it

 

[duraleigh]

Too many questioners to keep this thread on track.....this thread belongs to the OP - nabin.

nabin, 5 feet below is a big lift for any system and the tiniest air leak (on the suction side) will prevent priming. 2 minutes is about the max I would let a pump run dry. You need a check valve on the suction side and you need to look for suction side leaks.

 

[nabin]

 

[nabin]

I am attaching picture of pool equipment (please note - sand filter Pentair SD80 is removed for replacement) and pool.

 

[nabin]

Could you post a picture of your pool and your plumbing layout? An inground pool pump should not have that much difficulty catching prime and an hour is much too long a time to run "dry". Does your pool have an attached spa?

Could you post a picture of your pool and your plumbing layout? An inground pool pump should not have that much difficulty catching prime and an hour is much too long a time to run "dry". Does your pool have an attached spa?

Thank you, I just attached pics.

 

[zea3]

Nabin I would add a check valve on the suction side as Duraleigh was saying. Have you noticed if all the water drains out of the pump when it is off? Has the filter been replaced yet?

 

[Rocket J Squirrel]

This would be the opportunity to add the check valve. With the filter out of the way, this would be the time to move the pump back enough to make room for the check valve. It looks pretty close right now.

 

[nabin]

1. I will add check valve (Thank you for the advice)
2. Filter is not replaced yet - I am in dilemma on what to replace with (old Pentair sand SD80 leaked and I notice crack inside, so do not want to repair). Recommendations on the filter size and type including brand? I want advise on "low maintenance" hands off type of filter replacement
3. The pump and motor - I notice motor gets hot while running - could this be a sign of deterioration of motor and needs replacement? I'm willing to upgrade to variable speed motor/pump if someone can prescriptively tell me what to buy
4. I have a pool technician who works on the side and can do installation

 

[zea3]

If your motor is noisy and disturbs you or you want to take advantage of the flexibility of programable run times and speeds you could get a new VS pump, but if your pump is working fine you don't have to change it out. A sand filter is probably the least trouble, since you just backwash and rinse when needed. DE filters and cartridge filters perform a little better filtration wise, but you have to dispose of spent DE when its time to clean the filter, and cartridge filters have to be taken apart, cartridges removed to clean. Cartridge filters waste less pool water in the cleaning process, however. They all have pluses and minuses. If you get the largest filter you can afford you will clean it less often, and that is true for any type of filter.

 

[1Sammy]

A leak in the filter will let air in on shut down and cause the system to need to be primed as Jimrahbe mentioned. If all is tight the water will stay in a closed system.