Sump Pump switch too low?

[wastedthelight]

The basement in our new house floods a bit during heavy rain. It comes in mostly where the poured wall meets the floor, but also have cracks in the floor (stemming from the same place) leading to the center of the basement that water comes up through. We had a professional come out, his company specializes in dry basements and installing drain tile. I can't wrap my head around his observation. He said all we need is a stronger sump pump and move the trigger up more so the pit fills up higher, he suggested about 4-6 inches from the top of the pit. He said this will allow the pump to keep up, removing water from the drain tile before it fills up.

What I don't understand is if the pump kicks on at 1ft of water, what difference does it make if it's kicking on at 2.5ft of water? That means more water is in the pit, filling the drain pipe up completely and causing the water incoming to fight harder to get into the pit and causing water not to be removed as quickly which would push more water into the cracks, no? The pump is coming on and keeping the pit drained, even if it is constantly running, how does it "get rid of more water faster" if it's running less and filling up the pit? Also during non super rainy times, it would take forever for the pit to fill and drain the water, so the pit could have 2ft of water just sitting in there instead of the normal couple inches.

I was happy though that instead of saying I needed $7-10k drain tile it's just a sump pump setup issue though...but I just don't understand. We had a lot of flooding recently so these guys are super busy. The other professionals we have scheduled can't make it for another 1 month and 2 months...but we are on their list.

Notes:
- We have a sump pump (1/3hp, he recommends 1/2).
- Sump Pump switch triggers at about 1ft, when the water hits the bottom of the drain pipe
- Heavy rains its kicking on every 10-15 seconds
- Pit is about 3ft deep
- Bottom of drain pipe sits 1ft up from bottom, 2ft from top of pit
- He said we have drain tile on the outside of the house
- We also have a floor drain on the other end of the basement for whatever that info is worth.

 

[Geofd]

Why don’t you try a test , if your float is on a cord some of the cord can be pulled out so the water will get higher,
Unplug your pump
Fill the pit
Plug it back in
Then start filling the pit with water again
See what happens
You haven’t said the age or condition of the pump
How far it has to pump before gravity takes over

 

[wastedthelight]

Why don’t you try a test , if your float is on a cord some of the cord can be pulled out so the water will get higher,
Unplug your pump
Fill the pit
Plug it back in
Then start filling the pit with water again
See what happens
You haven’t said the age or condition of the pump
How far it has to pump before gravity takes over

The float is built into the pump, though I could buy a piggy back float switch cheap. Pump is brand new as of October. It actually was dying when we viewed the house so the seller put a new one in....but this guy said it should be 1/2hp instead of 1/3. About a 10ft verticals lift so that 1/3 is also just cutting it. But it does push and we have quiet check valves.

 

[Geofd]

The float is built into the pump, though I could buy a piggy back float switch cheap. Pump is brand new as of October. It actually was dying when we viewed the house so the seller put a new one in....but this guy said it should be 1/2hp instead of 1/3. About a 10ft verticals lift so that 1/3 is also just cutting it. But it does push and we have quiet check valves.

If you know the brand name/ model look up bpm it pumps and vertical capabilities (gpm) not bpm

 

[Dovid Elliot Gross]

When pumps kick in every few seconds, it is bad for the pump, and that's what is happening for you when it rains heavily. Better for it to run less often, and run for a longer period per run - the load on the motor and other moving parts is greatest while it is starting up. A less-sensitive float switch setup causes it to wait longer to cycle on. A more powerful motor clears the water faster, so it runs for a shorter period. The two together mean a more reliable pump and a greater period before it fails.

You may be able to get away with your existing pump on a less sensitive float switch setup, and it would both cycle off less frequently and cycle on less frequently, but it wouldn't be as safe - if the rain comes down particularly heavy for a short period, your current setup leaves more room for the water to build before flooding. WIth the less sensitive setup, the pump comes on when the pit is almost full, and if during that one period the rain draining has greater volume than the pump capacity, you'll flood. Hence, why you want a bigger pump if you change your float setup. It will come on less frequently because of the low sensitivity, and with greater power, it should be able to keep up with heavier rains, even with the reduced extra capacity of the pit.

But I might have a solution for you that meets all your needs. Keep the existing pump. Add a second, small pump, like a 1/4 hp utility pump or pool cover pump. Keep the pool pump on a sensitive float, perhaps slightly less sensitive than you have now. Because it is smaller, it will need to stay on longer to clear the medium buildup during dry weather. So the overall cycle will be a bit longer.

When it rains heavily, that pump won't keep up, but your 1/3 hp pump kicks in when the water gets higher. Both pumps working together will have a similar capacity to a 1/2 hp pump, so they should keep up. You can, of course, always replace the 1/3 with a 1/2 anyway if you want to be even safer.

Recommend only getting pumps with separate float switches.

This will require a plumbing change for the discharge pipes. You have a few choices here:

• If the existing pipe is large enough to handle the combines gpm capacities of both pumps, then you can add a Y connection to the existing pipe. Ideally, you'll have two check valves below the Y, but it may be OK to have a single check valve immediately above it. This is a cheap and easy modification.
• If the existing pipe is too small, then you need some new plumbing:
• ...either replace it with a larger capacity pipe with the Y configuration above
• ...or add a second discharge pipe with no connection between the two pumps