Strange noise from sump pump, when OFF (drain, install, plumber)

[hominamad]

Hi - I live in New York and we're having a crazy storm now, with flooding everywhere. I noticed a bad sound coming from my sump pump. Video below. The crazy thing, is that this is the sound that is coming out of it when OFF. In other words, when the pump kicks in, the noise stops. When the pump stops running, the noise starts up.



The thing that really has me perplexed is that this noise continues even if I unplug the pump. I assume this is not a good noise, but does this mean failure could be imminent? What could be causing this noise and why does it continue even after unplugging the pump? Needless to say I am going to have it looked at asap, but I'm curious what this is and how bad it could be. Thanks.




https://www.youtube.com/watch?v=TYoKzHoZIvw

[elnina]

The loud banging noise you hear when the sump pump turns on or off is caused by the check valve. ... This in turn shuts the check valve, preventing it from flowing back into the pump. The loud banging noise is caused by the sudden change in pressure inside the pump and its hoses.
You probably need to install a quiet check valve.
https://soundproofcentral.com/stop-s...banging-noise/

[hominamad]

Thanks - I actually saw that site already. It sounds like it's talking about a one time bang when it shuts off
This is like a continuous banging. I haven't heard it do this before.

[RamenAddict]

Originally Posted by hominamad

Thanks - I actually saw that site already. It sounds like it's talking about a one time bang when it shuts off
This is like a continuous banging. I haven't heard it do this before.

I had this problem and asked a plumber about it. He said the system looked fine, but if it is working hard, the system may start to shake/bang. In my case, when it stopped having to work so hard, the system stopped shaking.

[robr2]

Try changing out the check valve anyway. It sounds like the valve is opening and closing quickly with the water coming back down and the spring trying to push it back.

[hominamad]

Thanks everyone. Yeah I have to call someone, but it will probably be a few days or longer before someone can come look. I was just worried that the pump was about to fail and in that case my basement would be completely full of water. It made it through the night, but still making the same noise.



I definitely think its something physical, like the weight of the water pushing back on the valve, like what robr2 was describing. Since it still makes the noise when unplugged, it must be something like this.

[harry chickpea]

It is definitely chattering; but chattering from a single source extinguishes over time. Is/are there other pumps that feed into that drain line? Does the chatter go on for more than ten seconds?

In addition to replacing the valve, I would verify the float level in the sump is set properly, and I might change the pipe configuration to have the pump feed into a straight capped pipe with a side connection about a foot down from the top. The trapped air in the vertical section would then at least minimize the hammering damage if it couldn't be eliminated.

[Hemlock140]

I would say that there is no problem with the pump, but there is a lot of pressure on the backflow valve with a lot of water from the flooding. I am confident that it will stop once the floods subside, but would still prefer to have someone check it, since there could be debris keeping it from closing completely. That will cause water to come back in and be pumped out repeatedly, and run up your electric bill.