Automatic bilge pump, on or off?

Bluetack42

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I have owned a 12 year Beneteau for the past 8 years, it has an electric bilge pump which can be operated by either forcing on or selecting a float sensor in the bilge. The boat is kept in a marina on shore power, when I leave I always switch the main isolators to off, both to protect the batteries & a fear that live panels could be a fire hazard. What has recently occurred to me is that because this de activates the bilge pump I may be taking a greater risk of sinking if there was a seacock failure, would I be better to leave the power on? Which is the greater risk fire or sinking? What do other people do?
 

Rappey

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The whole point of those switches is to leave on in auto. No power consumption unless it turns on.
Ideal for open or leaky boats.
 

jwilson

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If a seacock fails on an unattended boat no bilge pump or battery bank will cope for long. I am happy my seacocks and piping are sound, as is the stern gland, and leave the bilge pump switched off when the boat is unattended, as it was for months this year. Fire from wiring probably a far higher risk than a sound seacock or piping failing. I would only leave a pump on (in auto) if I knew I had a slow leak such as from a stern gland, or a keel-stepped mast that always let a bit of rainwater into the bilge (as many do).
 

James_Calvert

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What do other people do?

I don't have an electric bilge pump, let alone an auto one.

And don't have shore power.

So no dilemma for me!
 

Caer Urfa

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Seems a silly question to me Surely the whole point of an automatic bilge pump is to protect the boat when your not there, agree with others just leave it in 'Auto' and wired to your domestic battery NOT your started battery.

I tested mine every month just to make sure it worked ok as the risk of flooding is far greater than the pump catching fire
 

rogerthebodger

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I also have my bilge pumps on auto powered by their own overload direct.

I also have some of my solar panels wired direct via their own overloads to keep the batteries topped up all the time.

I also have electromechanical counters wired across the bilge pumps so when I return to the boat I can check if and how many times the auto pumps have operated.
 
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Refueler

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I have an auto pump .. its wired via a 3 position switch :

Auto - OFF - Manual ON

The only time I have it fully OFF is in winter ... because we freeze !! Pumps don't like being frozen - so I lift it out and prop it up out of the bilge ...

Soon as winter is over - its back in the bilge and back on Auto.

My Mains power is connected all time ... and battery charger is served by timer .... through solid state splitter to the two batterys. That way they only receive a short top-up each day of 5 .. then 2 days rest in a week.
 

LONG_KEELER

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Definitely auto for me. If there was any way in which shore power could kick in after the batteries are done even better.

This month I had a 1 1/2" toilet seacock leak after relaunch.

Back in my berth, I calculated 3 to 4 litres of seawater every twenty minutes. This was leaking from the seacock body and not the cone. I have a manual pump down below and one worked from the cockpit.

No idea why the seacock started to leak . It would not have been possible for a travel lift strop to upset things.

The boat was new to me last spring 2019. Both of the toilet seacocks were seized on purchase of the boat. I had to give them quite whack to free them.

Lesson learned. Always remove seacocks that are seized and free them on the bench, then re bed. On purchase of a boat, re bed all through hulls
when you get the chance.
 

Refueler

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Definitely auto for me. If there was any way in which shore power could kick in after the batteries are done even better.

This month I had a 1 1/2" toilet seacock leak after relaunch.

Back in my berth, I calculated 3 to 4 litres of seawater every twenty minutes. This was leaking from the seacock body and not the cone. I have a manual pump down below and one worked from the cockpit.

No idea why the seacock started to leak . It would not have been possible for a travel lift strop to upset things.

The boat was new to me last spring 2019. Both of the toilet seacocks were seized on purchase of the boat. I had to give them quite whack to free them.

Lesson learned. Always remove seacocks that are seized and free them on the bench, then re bed. On purchase of a boat, re bed all through hulls
when you get the chance.

Second lesson learnt ... NEVER whack a seacock !! Unless boat on shore and you can fix the results properly before launch !!

I have a seacock inlet for my Blake ... but also a second valve in the line ... the main is seized open and I am not going to disturb it till boat is lifted ..... I can live with using the second valve till then !
 

NormanS

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If I had either an open boat, or a leaky boat, I might be tempted to have and use an automatic bilge pump. As I have neither, I don't.
 

ithet

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Like you I have a Beneteau of similar era. I have the bilge pump positive wired to the unswitched side of the battery but the negative is wired to the switched side of the negative master switch you get on these boats (I have all negatives through this switch). During the season afloat I leave the negative master 'on' permanently (i.e. also when leaving the boat), this allows the bilge pump (and gas alarm and battery monitor) to remain active. If necessary and on winter layup I can disconnect all electrics by switching of the negative master.

BTW make sure that the bilge pump selector switch is wired so that the power light only comes on when the pump is activated, mine was wired so that the light was on all the time there was power.
 

LONG_KEELER

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I can understand not having an auto bilge pump with the advent of drip less shaft seals . It comes down to personal choice and confidence in one's ship.

I like the idea of a roving power pump that would be independent from the boat's power supply. I purchased a "drill" pump from Machine Mart for around £12. It shifts incredible amounts of water quickly using a 240v drill . Unfortunately it won't shift anything with my cordless drill. It needs a minimum of around 2000 revs.
 

Denek

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We don’t have an auto bilge pump. We are on a swinging mooring and always close seacocks when we leave the boat so pipework should not be an issue. As previously stated if a seasick fails I would think an auto pump would never keep up.
we have a keel stepped mast and so after rainfall we get a little water in the bilges but not much. I always switch off electrics when I leave the boat and we have a small solar panel keeping the batteries charged. Not had a problem.......yet.....maybe I should not have said that?
 

Bluetack42

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Thanks for all this advice, its really helpful.

What I conclude is that this is a choice between two very unlikely but potentially catastrophic events, people clearly think about the issue but thankfully no one seems to have lost a boat, although there have been a few leeks. So instinct rather than experience guides peoples responses, my outtake is that there is a consensus towards leaving the pump permanently on auto when the boat is in the water, ideally reconfiguring the wiring as ithet describes.
 
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