Two bilge pumps or one big pump as secondary

[LadyAnya]

I am finally installing bilge pumps in my 24ft sunrunner. I currently have a 1500gph pump and I know I need more. I was thinking of using a 2000gph in conjunction with the 1500gph as sencondary pumps. Does it matter if I use 2 pumps or 1 big pump? I am planning on using a 600gph pump as primary.

 

[nikon]

Re: Two bilge pumps or one big pump as secondary

It's more plumbing and wiring, but I'd rather have two...just as a backup

 

[LadyAnya]

Re: Two bilge pumps or one big pump as secondary

I read somewhere that each pump should have its own thru-hull fitting, is that correct?

 

[JoLin]

Re: Two bilge pumps or one big pump as secondary

I read somewhere that each pump should have its own thru-hull fitting, is that correct?

That's best, yes. I'd also consider using the smaller pump as your primary to take care of rain water and spray. 1500 gph is more than enough (actually, 500 gph is plenty) for that purpose. Mount the float switch on the second pump an inch higher than the primary's, so it'll only kick on if the water level continues to rise (as in, you sprung a leak). David Pascoe has a good article on choosing and installing bilge pumps. Google his name and you'll find his website and articles.

My .02

 

[Home Cookin']

Re: Two bilge pumps or one big pump as secondary

another thing to consider--and the information is not hard to find--is that the GPH rating is the rating as if the pump was pumping out horizontally. You loose capacity as your hose rises, and most bilge pumps rise one to three feet (you want the through-hull to be high).

 

[mphy98]

Re: Two bilge pumps or one big pump as secondary

Two pumps are always better than one. and yes as stated before each plumbed separately. This will make sure water does not recirculate back into the boat. I have two and one has an automatic switch so if it rains and I am not with the boat by the dock, it can switch on and prevent sinking. Last year up in Canada we came in as it was just starting a downpour and I did not put up the convertable top and side windows as it was lightning out, and we got 2 inches of rain in an hour and a half. Most boats were very low in the water. Mine was high and dry. The others had to wait until their pumps were turned on manually befor they could go fishing again. I did not!

 

[cr2k]

Re: Two bilge pumps or one big pump as secondary

The loss of pumping is minimal in this situation as it equates to 5 psi per 10 feet of rise (head).
Either 2 thru hull or a diverter with a check valve between them.

 

[5150abf]

Re: Two bilge pumps or one big pump as secondary

3 pumps is ort of over kill as far as I am concerned but redundant is always good, better to have them and not need them I geuss.

As someone said mount the 600 lowest so it gets rain water then the other 2 slightly higher so they don't kick on everytime it rains.

Also I put an alarm on my big pump, have a 500 and 1100, so when the big pump kicks on I know I have a problem, like leaving the plug out, you know right away and avoid problems.

 

[LadyAnya]

Re: Two bilge pumps or one big pump as secondary

Thank you all for the responses.

I think the way I asked the question gave everyone a different idea about what I wanted to know. What I meant was, can I use two back-up pumps aside from the primary everyday pump? Since I already have a 1500gph pump, I wanted to add another 2000gph pump instead of buying a more expensive 3500gph pump as my back-up. 2 back- up pumps equalling to 3500gph and 1 primary 5 or 600gph.

 

[Home Cookin']

Re: Two bilge pumps or one big pump as secondary

you can add the gph of the pumps together only if each has its own hose to a through-hull. your plan sounds good

 

[LadyAnya]

Re: Two bilge pumps or one big pump as secondary

Great. Thanks again