# Combination Sump Pump vs 2 Dedicated Systems



## AlabamaSummers (Feb 14, 2017)

Hey, guys,

I was told recently that 2 dedicated sump pumps are better that a combination sump pump for a home. The reasoning was that if one component breaks on the combination sump pump, the entire system goes down.

On the other hand, if you have two dedicated sump pump systems (one in which has a battery backup), you won't encounter this problem.

What do you guys think?


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## hdavis (Feb 14, 2012)

I did that after I had a system fail leading to a cellar flooding. It's rare to have a fail.


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## AlabamaSummers (Feb 14, 2017)

Even though it's rare, I guess you're for getting two separate dedicated systems with one of them having a battery backup, right?


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## MarkJames (Nov 25, 2012)

Do you mean a main and a battery-operated back-up? There are combo units with those two separate units), so they basically save you some plumbing discharge work in the pit. Battery sold separately.


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## Rio (Oct 13, 2009)

AlabamaSummers said:


> Even though it's rare, I guess you're for getting two separate dedicated systems with one of them having a battery backup, right?


If it's a critical area where you really don't want it get wet then it would seem to be well worth the additional cost and hassle.


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## MarkJames (Nov 25, 2012)

Don't forget a water alarm (or two) placed on the floor nearby. Cheap insurance.


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## hdavis (Feb 14, 2012)

MarkJames said:


> Don't forget a water alarm (or two) placed on the floor nearby. Cheap insurance.


Doesn't work well if nobody is home, but it's still worth it.


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## tgeb (Feb 9, 2006)

The combination units I have seen have 2 pumps which will work in tandem if the primary pump is overwhelmed, and one will work as battery backup in the event of power failure.

Are you thinking of having two separate sumps and systems? Not real clear what the question is.


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## AlabamaSummers (Feb 14, 2017)

MarkJames said:


> Do you mean a main and a battery-operated back-up? There are combo units with those two separate units), so they basically save you some plumbing discharge work in the pit. Battery sold separately.


Hi, Mark,

Yep, I meant a main and a battery operated back-up. I was asking whether the combo units are better than having two separate systems. One main. And another separate system with a battery backup.


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## AlabamaSummers (Feb 14, 2017)

tgeb said:


> The combination units I have seen have 2 pumps which will work in tandem if the primary pump is overwhelmed, and one will work as battery backup in the event of power failure.
> 
> Are you thinking of having two separate sumps and systems? Not real clear what the question is.


Hi, tgeb,

I know about the combo units. I meant totally two different systems. I was told that the combo units can fail (they said they've seen it happen) because if a certain component breaks in the combo unit, the entire system can fail. They said it's better to get two separate systems.

I'm wondering how true this is.


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## rrk (Apr 22, 2012)

A battery backup pump will not pump for long especially when you need it the most, maybe 2 hrs

I have a few customers who found out the hard way, if you have city water check out water powered back up pumps. Uses no electricity, pumps out 2 gallons for every 1 gallon used


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## Windycity (Oct 3, 2015)

rrk said:


> A battery backup pump will not pump for long especially when you need it the most, maybe 2 hrs
> 
> I have a few customers who found out the hard way, if you have city water check out water powered back up pumps. Uses no electricity, pumps out 2 gallons for every 1 gallon used




I have been thinking of getting one of those myself. The only problem is you need to make sure you have sufficient water flow to the unit to create enough suction


Sent from my iPhone using Tapatalk


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## rrk (Apr 22, 2012)

Windycity said:


> I have been thinking of getting one of those myself. The only problem is you need to make sure you have sufficient water flow to the unit to create enough suction
> 
> 
> Sent from my iPhone using Tapatalk


yes, everyone I see has a 3/4" line. But they work great and the discharge line has to be above ground so you know its pumping but with the amount of water coming out it is a bit noisy


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## Big Johnson (Jun 2, 2017)

rrk said:


> A battery backup pump will not pump for long especially when you need it the most, maybe 2 hrs
> 
> I have a few customers who found out the hard way, if you have city water check out water powered back up pumps. Uses no electricity, pumps out 2 gallons for every 1 gallon used


They’ll last longer than 2 hours but it all depends on the battery size. A 45amp hour will last about 2 days pumping every 5 minutes.


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## hdavis (Feb 14, 2012)

If I had to go with a battery backup, I'd make that use a 12V bilge pump. 5A draw to get 1250 gph into a 5 foot head, for instance. Way more efficient use of the juice.

The last sump pump fail I had was the check valve, which came loose inside and erratically blocked the outlet.


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## rrk (Apr 22, 2012)

Big Johnson said:


> They’ll last longer than 2 hours but it all depends on the battery size. A 45amp hour will last about 2 days pumping every 5 minutes.


I can positively tell you that the battery that comes with that pump does not last that long.

2 different customers one lasted 2 hours 1 close to 3 hours

Another one had a drainage system installed in their basement with one and that only lasted 2 cycles when the customer decided to test it by unplugging main pump. But I think that was a defect with pump or battery since it was brand new


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## hdavis (Feb 14, 2012)

Doing one from scratch knowing what I know, I'd use 2" pipe and no 90 elbows If it's any real length. It improves the pumping efficiency, so less power is used. It also increases flow rate. I've seen systems that under the right conditions it can't keep up with the water coming in.

They're cheap, over engineering them isn't much money compared to what can be lost.

BTW, Attwater bilge pumps are the most efficient ones out there, but they won't work well if there is too much head.


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## Golden view (Feb 16, 2012)

rrk said:


> A battery backup pump will not pump for long especially when you need it the most, maybe 2 hrs
> 
> I have a few customers who found out the hard way, if you have city water check out water powered back up pumps. Uses no electricity, pumps out 2 gallons for every 1 gallon used


If it were my house, I'd consider the battery back up something to keep me dry while I get the generator out.

The systems used here use large batteries and claim 12,000 gallons on a battery.


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## MarkJames (Nov 25, 2012)

Near our sump is an existing floor drain connected to the sanitary waste. No longer legal, but I'm certainly not removing it.


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## Robie (Feb 25, 2005)

hdavis said:


> Doesn't work well if nobody is home, but it's still worth it.


This works if you're not home. I bought one a few years ago and it works great. I was having trouble with copper pipes entering and existing my oil-fired-boiler leaking.

I paid half the price of what it is now.

https://www.amazon.com/gp/product/B00PVDUYPM/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1


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## Big Johnson (Jun 2, 2017)

rrk said:


> I can positively tell you that the battery that comes with that pump does not last that long.
> 
> 2 different customers one lasted 2 hours 1 close to 3 hours
> 
> Another one had a drainage system installed in their basement with one and that only lasted 2 cycles when the customer decided to test it by unplugging main pump. But I think that was a defect with pump or battery since it was brand new


That system doesn’t come with a battery, just the box.


https://www.sumppumpsdirect.com/Wayne-WSS30V-Sump-Pump/p7283.html


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