Normal noise level of pump....

[peter.bastian]

My Northstar pump periodically seems to have an increase in the decibel level of it's background noise level. I can only describe it as follows: its louder than normal, and seems "coarser", not as smooth, as if there is some air or other material slogging around in there to make it louder. Also, I have this curious observation - if I apply backpressure on the system (on the order of 2 psi), by slightly closing the valve to the pool return jets, the pump gets quieter, more like the normal level of background noise from the pump.

Any thoughts on this and whether it represents some sort of problem? Has anyone else experienced this?

 

[JohnT]

It could be that the water flow into the pump is slightly restricted. Closing the valve to the returns reduces the flow out of the pump allowing the suction-side plumbing to supply enough water to the pump. Is everything clear and open on the inlet side (skimmers and drains)?

 

[mas985]

It could be that the water flow into the pump is slightly restricted. Closing the valve to the returns reduces the flow out of the pump allowing the suction-side plumbing to supply enough water to the pump. Is everything clear and open on the inlet side (skimmers and drains)?

Mine gets a little louder when the vacuum is engaged and gets much quiter when solar is engaged. For most pumps, when the vacuum gets high compared to the return pressure, the pump gets louder. When the vacuum is lower or return has higher pressure, the pump will get quiter.

Sometimes too when the head loss is very low on both the return and suction, flow rates can get quite high which can also cause a loud pump.