Multiple Check Valves in Sump Pump Install

[LeftyLoosey]

Last week I posted about getting a new sump pump and battery backup installed in my basement. Initially when the installer put in the new submersible pump he put a check valve in about halfway up the discharge pipe - approx 3' up from the pump. The pipe then continues for another 3' or so before turning and exiting the basement. I had a different company install the backup pump and they took this check valve out and put in a check valve at the base of each pump. The system seems to be working fine but when the sump pump finishes running all the water in the approximate 6' of discharge line runs back down as the original check valve is no longer there.

I've read one of the reasons for the check valve is to prevent the pump from re-pumping the same water and to relieve some of the strain on the pump over time. It's also fairly loud when the water is running back down the pipe.

I have the original check valve and it would be a very simple matter to reinstall it in the vertical discharge line a couple feet above the 2 pumps. Is this a good idea to do? Is there any reason NOT to do this?

Thanks.

 

[Twowaxhack]

The closer the check valve is to the pump the less water runs back into the pit.

Don’t install two check valves in the same pipe.

Follow what the directions say that came with the pumps.

 

[RS]

I don't understand, if there is a check valve at the pump why is the water running back? If that is happening the check is not working and should be replaced, one check valve near the pump is the normal way to do it.

 

[LeftyLoosey]

RS I agree - unless I'm assuming both pumps have check values on them and one doesn't. I don't know if this matters but they did not run a separate discharge pipe for the backup pump. They plumbed the backup pump into the main discharge line about 1ft up from the main pump. I'm going to go down today and do a test on the backup pump and will see if I get the same sounds when pumping from the backup.

I'll probably have to call the installer to come back and check things out.

 

[sawguy]

I don't understand, if there is a check valve at the pump why is the water running back? If that is happening the check is not working and should be replaced, one check valve near the pump is the normal way to do it.

It sounds like he hears the water running back to the check valve, not the pit.

 

[LeftyLoosey]

So I went downstairs, unplugged the main pump and filled the pit with water until the backup pump turned on which it did. When the backup turned off it was dead silent. No water running back down the pipe. When I then plugged in the main pump it turned on but when it was done I could hear the water running back down the vertical part of the discharge pipe (about 6'-7' total height).

 

[Twowaxhack]

So I went downstairs, unplugged the main pump and filled the pit with water until the backup pump turned on which it did. When the backup turned off it was dead silent. No water running back down the pipe. When I then plugged in the main pump it turned on but when it was done I could hear the water running back down the vertical part of the discharge pipe (about 6'-7' total height).

The check valve on the main pump sounds like it’s not checking.