Pump Problems

[sgreiner1011]

I just bought a house is AZ and it has a pool. For some reason I can hear air inside my pump and ts pretty loud. I cannot see air through the basket lid, but I can hear it. I replaced all the seals in the motor and pump housing, replaced the Jandy valve seals, replaced the basket lid oring, took my DE filter apart and cleaned it, poured water all over the connections to see if it would go quiet, and I still hear the air. My psi is at about 12. When I turn the sprays on in the pool, the pump goes quiet and the psi jumps to 30 and water comes out of this open pipe coming out of the ground next to the filter. What is that pipe? I have a robot that cleans the bottom of the pool and when I turn that all the way on, a massive amount of air gets into the pump and I can see it through the basket lid. But still when I turn the sprays on and the robot on full blast together, the pump still gets quiet.

Bottom line is the pump always gets quiet when I turn the sprays on and it doesn't matter what else I have on (robot, skimmer, etc.), but water comes out of this open pipe that I have no idea what it is. Is my pump too big for my pool? I am at a loss. Thanks

[PoolDoc]

I'm not sure at all, what you are hearing. Normally, if you have a transparent pump lid, and don't see air, it's EITHER completely full of water (no air) or completely empty (no water). So, I'm not at all sure the noise you hear is air.

I've explained a common piping problem that MIGHT be your problem below -- but this is just ONE possibility, among many.

Your best bet is to take photos and send them to poolforum AT gmail DOT com, and let me post them. Several people here could help you, and with photos, we could do more than just guess.

It sounds like you've got pump system noise, that stops when you restrict the flow enough. But, that's not air. If you've got enough flow, and have Jandy valves installed in the common and idiotic "butt-head tee" arrangement, the noise may simply be high flow + bad piping.

I'll explain.

Tee's can be oriented several ways in piping. A "branch tee" is a hydraulically acceptable way to split a branch OFF, or to combine two flows. BUT, the smaller flow should ideally be on the branch side, like this:



Another way to split flows is the "bullhead tee" arrangement, where the main flow comes in the branch and exits through the two opposed sides, like this:

This not good, and is hydraulically inefficient (lots of pressure loss!), but it's acceptable at lower flow rates.

What is NOT acceptable, is the "train-wreck tee" layout:



This layout is so bad, that there are not any published pressure drops for this arrangement. Presumably, the guys who make those tables and charts assume that if you know enough to use a pressure loss chart, you know enough. If you've got that layout AND high flow, you noise could be one of the trainwreck tees.

Here are some real world examples:




The picture above is interesting, because the Jandy valve on the LEFT is in "train-wreck" configuration, but the one on the right is in "bullhead" configuration.


And, this one is actually NOT a tee, but an ell, since EITHER the spa OR the pool operates. The valve is currently in pool mode, with the spa closed off.

[mas985]

It sounds like it might be high flow rate noise to me as well. Most likely in the pump itself. Can you describe your equipment and plumbing? Pump size/model, plumbing sizes, lengths, numbers of runs to and from the pad, etc.

[PoolDoc]

Thanks, Mark. I should have made it clear that the noise itself was likely to be in the pump, but that the restriction that caused the noise can be elsewhere.

[PoolDoc]

Sgreiner's pool equipment:

[PoolDoc]

OK.

I don't know what the problem is. The piping is not great, so you could try operating on skimmer only, and see if that causes the pump to run more quietly.

Also, the pump itself looks pretty old - some types of pump wear can cause noise, as can trash caught in the impeller. But, some of those old pumps were pretty noisy when they were new.

[mas985]

Ben,

The OP indicated to me on another forum that they cannot respond to this thread anymore. Can you check this out.

[PoolDoc]

Thanks, Mark. I'd failed to update their access; I'll let them know that's no longer the case.