Cruisers Forum

Join CruisersForum Today

Thread Tools Search this Thread Rate Thread Display Modes
Old 08-04-2017, 12:12   #1
Registered User
Lennie's Avatar

Join Date: Dec 2008
Boat: Jeanneau 43 Deck Salon
Posts: 122
bilge pump plumbing

I want to install another electric bilge pump and want to know if I can just plumb the output to the intake of the manual pump? Will it pump through it?



Lennie is offline   Reply With Quote
Old 08-04-2017, 12:44   #2
Registered User

Join Date: May 2012
Location: Halifax, NS, Canada
Boat: 47' Steel Roberts Cutter
Posts: 260
Re: bilge pump plumbing

You may be able to pump through it, depending on the arrangement, but it is not a good idea for many reasons:

- the flow restrictions imposed by the valves in the manual pump will reduce your electric pump output significantly.
- redundancy between manual and electric bilge pumping is usually desired.
- any debris picked up by your electric pump will get pushed through the manual, and possibly clog it, thereby taking out both pumps.
- the efficiency of the manual pump will also suffer, since now you're sucking through a less-than-ideal 'strum-box' (the electric pump).
- in real flooding situations, you are already using up the discharge capacity of both pumps with the electric - even if you have extra hands available to wag the handle of the manual, you won't be able to push more water through that single line and increase the ability to dewater.

In short- don't do it.

One thing you can do is plumb it into a cockpit drain line if you have one... this saves a thru-hull sometimes; but it too can have undesirable side-effects.

Really, all bilge pumps should have their own suction and discharge lines, all the way from bilge to overboard.

NSboatman is offline   Reply With Quote
Old 08-04-2017, 15:04   #3
Senior Cruiser

Cruisers Forum Supporter

Join Date: May 2013
Location: Oregon to Alaska
Boat: Wheeler Shipyard 83' ex USCG
Posts: 2,117
Re: bilge pump plumbing

Someday you may need both the electric and manual. I've been around docks all my life and seen a few boats sink and a number come close. Most often it was the bilge or shower pump. Even a 100' tug once.
Many people screw up bilge pump installations. Some sink their boats. You need a loop with a suction break so the line can't siphon water back into the boat if the outlet is forced underwater. Check valves aren't reliable because bilge debris can hold them open. New bilge pumps usually come with a diagram of a proper installation.
Lepke is offline   Reply With Quote
Old 10-04-2017, 07:57   #4
Registered User
Lennie's Avatar

Join Date: Dec 2008
Boat: Jeanneau 43 Deck Salon
Posts: 122
Re: bilge pump plumbing

Thanks for the replies, I'll plumb it in as a stand alone unit
Lennie is offline   Reply With Quote

bilge, bilge pump, plumbing

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Best bilge pump to keep the bilge as dry as possible keelsidedown Plumbing Systems and Fixtures 24 30-05-2018 15:51
Bilge pump plumbing w1651 Construction, Maintenance & Refit 10 03-01-2016 15:18
Bilge Pump Plumbing Dilemma twistedtree Plumbing Systems and Fixtures 6 08-05-2011 15:36
1990 Wellcraft San Remo Bilge Pump Locations and Foul Bilge Smell skyinb Powered Boats 2 25-06-2010 19:21
Plumbing a Bilge Pump gettinthere Plumbing Systems and Fixtures 7 05-02-2010 15:38

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 22:55.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.