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 sump pump too strong?
Author: lindsay2020 (CA)

I have a 1/2 horse power sump pump hooked up to my kitchen sink drain which pushes the water up to our unit's drainage which is on the 2nd floor - approx 12 feet up (we live in a strangely configured loft unit). The neighbor's drain is connected to our upstairs drain and the pump is pushing dirty water up into his sink.

Also, I re-read the user manual for the pump, and it says to use 2" pipe but the professional plumber who installed it used 1 1/2" pipe. Could this be increasing the pressure to the point of causing the water to come out my neighbor's sink (which is approx another 8 or so feet of piping total, around 4 feet higher than where the pump discharge pipe feeds into the main drain)?

I am trying to decide whether to call a plumber to replace the 1 1/2" pipe with 2" pipe, or to purchase a weaker unit, which I can install myself. Any help would be greatly appreciated!!

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 Re: sump pump too strong?
Author: packy (MA)

snake the drain the pump ties into before doing anything else.

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 Re: sump pump too strong?
Author: lindsay2020 (CA)

Yes - we already snaked it...a couple times. It's definitely clear. The drain that it feeds into has a very slight "S" curve in it about 2 feet past where the pump pipe feeds into it, then after that it opens up to 4" pipe (from 2" pipe). I'm thinking the "S" curve, even though it is very slight, could be causing the water to "bounce back" because the pressure is too strong. Any thoughts on which is better - to increase the size of the pipe from the pump to the main drain, or to just get a less powerful unit?

Edited 1 times.

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 Re: sump pump too strong?
Author: packy (MA)

any possibility of draining straight into the 4 inch ?
hey, there are lots of sewer ejectors tied into 2 inch pipes and they have big powerful pumps that have no problems.
yours really backs up in a sink 12 feet higher ???
if there is any way you can post a couple of pictures someone may be able to see something else that could be wrong ??

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