Brand New Booster Pump Making Loud Noises

[smokey75]

Got a question that I'm hoping this forum can help with. I've read everywhere on my problem and am just not finding anything that matches my specific issue.

My old booster pump (Polaris PB4-60) started making really loud noises so I bought a new one and installed it. When I started the new pump up, it's making noises very similar to the old one. I took the whole thing apart again to make sure I didn't have anything in the intake line hiding somewhere and I did not find anything.

Water is definitely getting to the pump and through it. When the pump first starts, it runs quietly but after about 30 seconds to a minute in, it just starts making the loud noise again and continues for as long as the pump runs. Since it's brand new, I strongly doubt it's the bearings. Similar, the volute should be in good shape also as it's new. Any ideas on what could be causing the noise?

If you need additional info, pictures, etc. just let me know.

Thanks.

[Poconos]

Hi Smokey and welcome to the forum.
Would help if you could describe the noise as best you can. Squeal, grinding, hash type white noise like radio static? My first thoughts would be an air leak on the suction side causing air bubbles to be kicked around in the pump housing. Are there any bubbles in the pump basket? Next would be cavitation which is the formation of bubbles on the impeller under a high suction condition which can be caused by a partial blockage on the suction side. Something you could try is to open the pump basket lid and fire up the pump and let it run dry for a few seconds. Do this after you have run it and the noise occurs so the thing is at operating temperature when you pop the lid. Run it normally to get it to temperature and making noise, shut it off, pop the lid, and run it again for 10 seconds or so. See if it makes any strange noises both while running and when you kill power and it spins down. Won't hurt anything.
Something else.....when it gets to the point of making noise, if you shut it down for a couple minutes and start it up again does it get noisy immediately? I'm thinking a thermal issue of some sort but I doubt it.
Al

[smokey75]

Thanks for the response. I tried to make a recording of the sounds with the regular pump only and then with the booster pump on (booster is the part making the noises), but it just wouldn't turn out well.

The closest I can come to describing the sounds is a cyclical crackling sound. Possibly what you're referring to as white noise/static.

Since it's the Polaris Booster pump, should I still try the basket and running dry part? That sounded like it was specific to the main pump not the booster.

When I rebuilt all the connections again this morning, I made a point of checking water flow both from the filter unit to the Polaris Boost (suction side) as well as on the pool side. When the line to the pool is disconnected, a LOT of water flows through the system so not sure if limited flow is the issue.

Also, I tried the check of turning it off, waiting, turning it on and seeing if the same sound happens and if I wait only 5 minutes or so, the sound is back almost immediately. If I wait more like 30 minutes, it acts like I previously described where it takes about 30 seconds to start making the noise. I doubt it's thermal anyway as nothing is even remotely hot to the touch, but wanted to cover all your questions.

Thanks again for the help.

[Poconos]

I missed the booster pump part and I was thinking generic pump troubleshooting. I never dealt with a booster pump situation. The noise you describe sure sounds like air in the system though. Any air bubbles visible out of your returns or the polaris itself? It doesn't take much of a leak to let enoigh air in to mess things up. Right now I don't have any other ideas.

Anyone else out there with some words of wisdom?

Al

[smokey75]

I'm suspecting air in the line also, but I don't really see air coming out of the cleaner hookup. How do you troubleshoot where air might be getting into the system?

[Poconos]

If air is getting into the system it would be on the suction side of the main pump. As I said, never played with a booster pump but I am assuming the inlet to the booster is not under a vacuum like the main pump. May be wrong though. In any case one highly probable place is the pump basket lid. Another could be any non-PVC joints. i.e. black poly pipe, barbed fittings, and hose clamps. Next on the list would be valves and finally bad PVC joints. If it is air then you should see bubbles in the main pump basket. It's odd you don't see bubbles out the returns. First thing to try would be to get some silicone grease if you don't have some already, pool store, and then clean and lube the pump basket gasket. First try that and see what happens. If that isn't it we'll go to the next step.
Al