Timer & pump priming

[BeccaM]

Good morning,

We have a 18x36 in ground pool that is approx 4 feet lower grade than the pool pump and heat pump. We manually turn the pump on and off each day, but are considering more trips away this summer and therefore are considering a timer. When we switch off the pump manually, we also turn the handles that close off the water flow from the pool to the pump. This keeps the pump primed. If we were to use a timer, the handles would stay in the open position. My worry is that the water will not stay (due to gravity pulling the water back into the pool, which has happened in the past), the pump will drain, and will not be primed when the timer switches the pump back on. Is my concern valid? If so, does anyone have any suggestions? One option is to move the pump closer to the pool level, but that requires construction and $$

Thanks,
Rebecca

 

[Jimrahbe]

Rebecca,

In a well operating system, the pump will not drain back into the pool. I suspect you have an air leak which is allowing your pump to drain.

I suggest that you fix the air leak or install a check valve right before the pump.

Thanks,

Jim R.

 

[BeccaM]

Hi -

We do have a check valve before the pump (those are the handles that we close when we turn off the pump). We did have an air leak last year that was fixed and we rarely lose our prime now. My concern is if we leave the check valve open and use a timer, gravity will pull the water back to the pool given the 4 ft difference between pool level and pump level, then we’d lose our prime and the pump would start unprimed.

Since the levers are manual, they are useless if we use a timer. Is there an automatic check valve option?

Thanks,
Rebecca

 

[Dave31410]

A check valve does not have a handle. It has in internal mechanism to prevent flow in one direction

 

[mas985]

My concern is if we leave the check valve open and use a timer, gravity will pull the water back to the pool given the 4 ft difference between pool level and pump level, then we’d lose our prime and the pump would start unprimed.

That will only happen if there is an air leak. As long as there are no air leaks, the pump will not drain.

 

[BeccaM]

A check valve does not have a handle. It has in internal mechanism to prevent flow in one direction

Thank you, I’ll look into getting one installed. When I googled check valve online I saw what we have, thus the confusion. .

 

[JamesW]

I would put the check valve at the discharge of the pump rather than the suction. The suction already has more head loss than ideal. No reason to add more.

A check valve at the discharge will be less likely to get clogged with debris since it's after the pump basket.

When you turn the pump off for 12 hours, the pump strainer should remain full of water. If it doesn't remain full, you have a suction side air leak.