Converted to Half PVC, No Flow to Return

[nowaksr]

Over the weekend, I partially converted our Bestway 20'x8' (4.2k gal) from 1.25" and 1.5" hose to PVC. We have the filter in the middle of one long side of the pool. The problem is we have a fence that is next to the filter and pool so every time we need to clean the filter, we have to squeeze between the pool and fence. The goal was to move the filter to the end of the pool and hard-plumb from the filter to the hoses. When I turned the filter on, I had no pressure at the return jet. I had water coming into the pump and leaving at the pump, but it would not make it to the return. My guess is too much for the pump? Mind you, I have limited plumbing knowledge. Basic house plumbing, drip irrigation, and the sprinkler system is the extent. Details of current configuration:

• For the pump/filter, we are using an Intex 633T cartridge pump/filter which claims 2500 GPH (1900 GPH turnover). I believe the HP is around 0.3-0.5, 1.5" fittings.
• For the inlet, we currently have 2 - 4' hoses @ 1.25" connected to a tee, which then converts to a 5' hose @ 1.5" that runs to the pump. The 2 - 1.25" hoses will be replaced to 1.5" when they arrive.
• For the return, one 5' 1.5" hose directly to the pump.
• If my calcs are correct; 18' of hose with 1.8 FoH, min 9 GPM requirement. If the specs on the filter are correct, I should get between 28-43 GPM.

This setup has worked well, now the conversion...

Leaving the hoses in-place; I moved the pump to about a foot past the end of the pool (first image). I then ran 1.5" Sch40 PVC from the pump to the hoses. This increased the total hose/pipe length to about 45' (+27'). I realize that the longer run means more work on the pump but thought that the increased pipe size would allow the water movement, I'm guessing that wasn't the case.

The second image is after it was moved back to its original location and connections. If I reduce the return from 1.5" to 1" PVC pipe, will that help move the water? I would think it would restrict it but don't know the detailed physics of water flow. I'm trying to avoid having to purchase a new pump and filter if possible but at the same time increase the movement of water around the pool. The third image contains my notes.

 

[Pv2]

how do you know you had flow through the pump? did you try with the pump running and the line disconnected from the filter body? double check any valves when everything is hooked up. if you have flow out the filter cannister it should make it to the pool. I can't imagine why it wouldn't if nothing is physically blocking the flow. I doubt the distance or hard plumbing would have any but the most minor reduction in flow.

 

[nowaksr]

I didn't turn the pump on after the connections but instead, removed the return line at the pump and had moving water. I figured since there was a good amount of water leaving the pump, then the extra 13.5' of 1.5" pipe was too much to push out from the pump. You're suggesting that this amount of extra run shouldn't cause the flow to stop?

 

[Bama Rambler]

Adding that much piping horizontally shouldn't affect the pumping greatly.
Are you sure you don't have some debris in the impeller, or maybe an airlock in the pump?
Those small pumps are very sensitive to airlock.

 

[nowaksr]

Adding that much piping horizontally shouldn't affect the pumping greatly.
Are you sure you don't have some debris in the impeller, or maybe an airlock in the pump?
Those small pumps are very sensitive to airlock.

You've got me thinking about airlock. I noticed that after I bled the air, then turned it on, there was a negligible amount of pressure coming out of the return. After about 30 seconds it would "burp" and had no pressure. I wonder if I need to heavily bleed all air. I'll try this and will report back.

 

[Bama Rambler]

That pump has an air bleed on top of the casing. I'd open that and let it run until you're absolutely sure there's no air in the lines.

 

[nowaksr]

I forgot to post back results. It was in fact airlock. I was opening the valves on the sides of the pool and always bleed the air on the filter side, but typically did not have to release the air on the pump side. Once I started bleeding the air on both, everything has been working well. Thanks for the help.