Sump pump cycling every 20-30 seconds after heavy rain

[itbedave]

Been awhile since I've posted, but I've got a new girlfriend and have questions about her plumbing. (No pun intended) 😂

She has a fairly new house - built in last 10 years - with a sump pit in the basement and a Zoeller pump she says she had a plumber install about 4 years ago. It seems to be working fine, but we've had torrential rains and flooding in SW Ohio this week, and right now, the pump is cycling every 25 seconds. I know that can't be good on a pump, but it is working. I've gone down a couple of times to watch it lower the water level only to see it fill right back up to activate the float switch quickly.

One of the issues might be that the pump is sitting on the bottom of the pit, which looks to be about 2' across and maybe 30" deep? I know raising the pump would prevent it from cycling so much in times like this. And I will say that most of the time, it never runs at all and the pit stays pretty dry. But I also know raising the pump means tearing into the plumbing, so I wondered about the advantages of installing a switch instead?

The second issue may be the check valve. The one I have at my house is very quiet and just has a flap. This one looks similar from the outside, but what I hear sounds like there's a ball in there that's falling down the pipe and bouncing to a stop when the flow stops? Am I crazy? Do those exist? I thought it was just a flap?

So, after watching the cycling process a few times, i see the float rise, the pump kicks on, I hear the flow of water up the pipe for about 5 seconds and the water level in the pit drop but not completely, as the pump nears the stopping point, I see water shooting out the vent hole in the side of the PVC, and then when the pump stops, I hear and see a lot of water drain back out of the pipe back into the pit, and hear that sound like a ball falling to a stop in the check valve.

I'm wondering if that check valve isn't doing its job and allowing too much water to drain back into the pit? Or not letting it flow out fast enough because of the ball? It's placed about 18" above the top of the pit FWIW. I've replaced my own before, so I was going to start there tomorrow.

So my questions:
- is the constant cycling like this under these extreme weather conditions going to kill this pump?

- should I raise it or get a switch to adjust the level at which it kicks on?

- should I replace the check valve?

- what have I missed?

Thanks in advance!

 

[Geofd]

I have a pit in my house also we haven't had flooding rains thou
Is there also a French drain collecting water from other areas???
my pump is about 15 years old it sits right on the bottom
there is no mud or debris right now I have a smaller pump
with an internal float I can run that outside never needed it
I have a brand new one I'm gonna install and pipe the smaller
one into the same drain some pumps you are able to adjust
the cord on the float so it won't come on as quickly but I think
were its set is were it should put a temp pump in there now
just for peice of mind I would change that 10 year old pum
yeh it still may have life left but if you install new you know it's
true age

 

[Mr_David]

If the pump is pumping out water you do not need to modify how it sits on the bottom. what you need to determine is where that water is gushing back into the sump.
Is it coming out of the bottom of the pump?
Sounds to me like a failed check valve.

there should be a manual valve on the discharge line after the check valve.
This will allow you to service the check valve and pump with out allowing the discharge line to drain completely back into the sump. If the riser is not very high then often they omit the valve.

disconnect the power to the pump before you try to take it apart.

If you did turn off power how fast does any addition water flow into the pit..

You could be just recycling the same water over and over again

 

[itbedave]

Thanks for the reply. I went back with a tape measure and my phone so I could take pictures and video.

Yes, the backflow must be coming out of the bottom of the pump. And no, there is no manual valve above the check valve.

Out of curiosity, I unplugged the pump while it was cycled off and watched the water level. It quickly rose just as before. I let it rise maybe another 3 inches over where it kicks on normally - just a little lower than completely being submerged - just to see if it would level out and it just kept coming. After plugging it back in, it quickly lowered the level as it's been doing.

So yes, I think I am getting some back flow. But I also think we've just gotten a crazy amount of rain. Still worried about how often it's kicking on.

Also, I measured everything this time. The pit is 20" in diameter x 24" deep, plastic lined. Looks fairly clean on the bottom. Just a little sand. The check valve is 32" above the discharge outlet on the pump. Above it, there's about 12" of PVC before there's an elbow, then another 18" of PVC and another elbow before it goes up and out of the house. Photo below.

I've got some video too so you can hear it if I can figure out how to post it.

 

[itbedave]

Another question I wanted to ask... If you look at the photo I posted, the vent pipe stops about 4" above the sump cover. Shouldn't that go INTO the sump cover? I believe the one at my house does but will have to look again.

 

[TomFOhio]

You don't need a vent on a regular unsealed sump pump system. Change out that check valve. Like the other posters said the water from your pipe is just running back into the pit. You might have water coming in from the footers and even underneath the floor. Your going to burn up your pump if you don't do something soon. Let us know how it turns out.

 

[itbedave]

Purchased the new check valve - which turned out to be identical to the old one (purchased from Lowe's), opened the pit and took some video and pics before and after the installation. I'll link to them as soon as I have them uploaded.

It was dry today for the first time in several days. So the cycling had already reduced itself from about about every 25-30 seconds overnight, to 45-50 seconds by the time I got home with the new valve today.

Upon taking the cover off and getting a closer look at the pit and pump, the pump appears to be sitting on a metal plate in the bottom of the plastic basin. It looks like after the pump cycles completely, there's still 2-3 inches of water in the pit. And with the airlock hole just above the discharge on the pump, it shoots a lot of water back into the pit as soon as it's halfway through it's cycle. Could that be part of the problem?

The two main drain tiles into the pit are a good 6" above the pump. (See photos) I could tell they still had water in them, but weren't currently draining anything into the pit. But it looked like smaller tiles connected into the bottom of the pit likely were the main source of water, and it was still refilling pretty quickly.

So, unplugged the pump and got the new check valve installed and got wet in the process as there was no upper valve to shutoff the backflow. Comes with the territory though. Easy to get the old one off and the new one in its place. Moved the pump around a bit to better align the discharge pipes as they were a little off before. I also let pit fill a little further to see if it would level off at some point, which it did about 3" above the level it would normally kick on. So I wondered if the pump is still sitting too low in the pit, causing it to cycle more often during rains like this.

The new check valve DID help. We're down to a cycle of 1 minute, 15 seconds now. The sound of it closing isn't nearly as loud, nor does it shake or "bounce" closed. Examining the old one, I could see the flapper was covered in mineral deposits and slime, and was likely not closing as quickly or tightly and allowing more water to backflow. The new one is much quieter.

Again, when I get my video posted demonstrating the cycling before and after, you can see your yourself.

Thanks again for the assistance!