2bilge Pumps Once Outlet?

[mphy98]

can you run a primary and a backup automatic bilge pump and run them out of the same outlet? if so i think i would need a oneway valve to prevent the 1st pump from backing up into the secondary pump. do they make such a valve for marine use on small hoses?

 

[Bondo]

Re: 2bilge Pumps Once Outlet?

Nope,...

Each pump needs it's Own Outlet.....

 

[tashasdaddy]

Re: 2bilge Pumps Once Outlet?

agree each should be totally independant. mine even run off separate batteries.

 

[wildmaninal]

Re: 2bilge Pumps Once Outlet?

If you are talking about the water outlet...... I run 2 bilge pumps out one outlet. One bilge I use for the livewell, the other I use for the battery/bilge area of my bass boat. I have one teed in with the other, plus I have check valves to prevent the one pump from pushing water into or through the other pump. So far it works great, and I've been using it for a while now.

 

[Baylinercapri1987]

Re: 2bilge Pumps Once Outlet?

I have it done on my bayliner, 2 pumps one outlet. I used a 3 way splice and a on/off valve for the aux. pump, works great.

 

[Gary H NC]

Re: 2bilge Pumps Once Outlet?

In an emergency situation where both pumps are needed to save the boat from sinking it will be restricted to the point of having the same pumping capacity of one pump.
The plumbing kit with hose and through hull fitting is about 10 bucks...well worth the added safety.

 

[salty87]

Re: 2bilge Pumps Once Outlet?

while it's possible to connect them that way, you can only pump so much water thru a single outlet. you're not really getting a true back-up that way. you're also reducing the flow a little bit with the check valve.

net gain from second pump hooked up like that is a slight reduction in flow.

i have 1 fat pump with a float switch. you don't want to be in the wrong spot at the right time when it kicks on...stand back. don't tie up to me on that side of the boat!

 

[Baylinercapri1987]

Re: 2bilge Pumps Once Outlet?

I did test that theory, and it seemed to pump 2-3 times faster when the aux pump turns on, It definitely worked for me.

 

[DJ]

Re: 2bilge Pumps Once Outlet?

can you run a primary and a backup automatic bilge pump and run them out of the same outlet? if so i think i would need a oneway valve to prevent the 1st pump from backing up into the secondary pump. do they make such a valve for marine use on small hoses?

NOPE! Two outlets (independent) needed. I do not want to fool with a valve when things go bad.

Even if you dump one hose into the motor splashwell, at least you'll know it's removing water. BTW, stay away from the "corrugated" hose. That stuff reduces pump efficiency by as much as 50%.

Smooth (inner) wall hose is preferred. Automotive heater hose works well. As long as it stays out of the elements (sun, ozone), it will last a long time. BTW, double clamp both ends.

 

[dtskidoo]

Re: 2bilge Pumps Once Outlet?

if you have 2 pumps for safty should have 2seperate systems. Check valves malfunction dirt etc. Thats my 2 cents worth.

 

[salty87]

Re: 2bilge Pumps Once Outlet?

I did test that theory, and it seemed to pump 2-3 times faster when the aux pump turns on, It definitely worked for me.

you may have been better off with a larger pump instead of 2.

 

[KLINDWW]

Re: 2bilge Pumps Once Outlet?

I think your original question was could you make it work and the answer is yes and the answer to how much flow it would gain you is a function of what size the bilge pumps are and what size and how long your discharge hose is. This a simple function of flow vs pressure drop through the hose. What everyone is saying is this is not the preferred method. There are many downsides but the one that comes to the top of my list is that you only have one discharge hose and one through hull fitting. This is not true redundancy.

 

[mphy98]

Re: 2bilge Pumps Once Outlet?

ok so i will drill a hole and put in another drain, will have to wait till spring time though, a foot of snow tomorrow, followed by 4" of snow sunday, followed by another 4" of snow tuesday, followed by another 6" on thursday. man it sucks to live up here but, i am gratefull for global warming or we cold be alot colder with alot more snow!

 

[5150abf]

Re: 2bilge Pumps Once Outlet?

As stated above, if you have 2 pumps that can pump 1100gph each but the hole the water exits can only flow 1100 gph you may as well not have the second pump.

I was going to put an elbow in my bilge outlet but changed my mind when I realized that would restrict flow, you want the pumps to pump all they can just in case.

I also reccomend you put an alarm on the second pump, I have 2 pumps-500 and 1100gph, both automatic with the 500 switched also, the 1100 is slightly higher in the bilge and has an alarm on it so when it comes on you know there is a problem, the smaller pump is free to run for rain water ect.

So now if I should launch without the plug I know almost immediately that there is a problem rather than running possibly miles from the launch before noticing I am sinking

 

[fishrdan]

Re: 2bilge Pumps Once Outlet?

Good to hear you are going to run separate hoses.

Another thing to consider, what if one of the bilge pump hose gets clogged with debris and stops/reduces flow. Now both of those bilge pumps have no where to push the water. It might seem far fetched, but I had my 1 and only bilge pump/hose get clogged in a nasty wind storm. Didn't find out until the engine died from being flooded and we had to dig all sorts of carp out of the through hull fitting and then pump the boat dry.

I installed a second high volume bilge pump and through hull fitting after that experience.

 

[tashasdaddy]

Re: 2bilge Pumps Once Outlet?

the reason i have 2 pumps, is that i had only one, and it went bad in the FL Keys, it was brand new. i had to pay about 3 times for a replacement, there as i would have at home. i had 2 bilge pumps in my shed at home, also.

 

[reelfishin]

Re: 2bilge Pumps Once Outlet?

Adding a redundant bilge pump just in case is cheap insurance. My one boat had 4 of them, one in the bow area, two at the stern and one to empty the live well.
The bow pump and one in the stern were automatic with manual override and the second stern pump was full manual and big by large. That one was there in case of emergency. I could set that one on auto as well if I was going to be away but it drew too much power to just let it run as the main pump. I had its float set higher so it wouldn't run unless the other failed.
The second stern pump was capable of somewhere in the range of 5000 gph and had a 1.5" outlet. Luckily I never needed it. The main difference in the wiring was that that pump could be turned off, while the other two bilge pumps could not. Each pump had it's own output hose and outlet, The bow compartment pump would exit via an elbow shaped stand pipe over the bow deck, the stern pumps exited out the left and right rear sides of the boat and the livewell pump dumped right out the side.

 

[special_kaye]

Re: 2bilge Pumps Once Outlet?

Running the rivers around here, or the mangroves going to the Gulf, it's very easy to take a branch through the hull. A small, say 2" hole, can put a lot of water in your boat very fast. My current boat only has one 1100 GPH bilge pump, with corrugated pipe. My refit budget definitely includes another pump, at least 1100 GPH, and smooth wall pipe for both. And yes, they'll be on separate through-hulls with an alarm for the second pump.

 

[David Greer]

Re: 2bilge Pumps Once Outlet?

add a hand pump for when your batteries are flooded, too, or to assist someone less prepared as we.
Even just to have a loose second pump and hose, with clamps on the wires, to drop in the bilge as a back-up is a good idea. Don't trust float switches; it's a $15 part insuring your $15000 boat.
I read about one guywho replaced a white deck plate with a clear one so he could see if his bilge was flooding.

 

[special_kaye]

Re: 2bilge Pumps Once Outlet?

add a hand pump for when your batteries are flooded, too, or to assist someone less prepared as we.
Even just to have a loose second pump and hose, with clamps on the wires, to drop in the bilge as a back-up is a good idea. Don't trust float switches; it's a $15 part insuring your $15000 boat.
I read about one guywho replaced a white deck plate with a clear one so he could see if his bilge was flooding.

Forgot to mention the hand pump. It's kinda like "standard equipment" to me and I don't notice unless it's missing. Really like the idea of the loose pump with battery clips. Kinda like the USCG pumps dropped from the helos. That'll go on my "things to get" list. Thanks.