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Automatic float switch recommendations?


Withywindle

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My wife and I are now proud owners of our first boat, a 15 year old Colecraft narrowboat. 

 

One of the comparatively few recommendations made by our surveyor was to fit an automatic float switch in the circuit to our bilge pump. This seems sensible and I was intending to go ahead, particularly as our boat will spend her winter on a marina and we will not be able to visit as often as perhaps we’d like, to check on her. 

 

Having said all of this, my research into suitable float switches has thrown up a few unexpected horror stories. These mainly involve them activating and getting stuck ‘on’ then burning out the bilge pump or running down batteries. One particular brand, Attwood, seems to come in for a lot of criticism in this regard. 

 

What are people’s thoughts on automatic float switches - a good idea or not? If so what is the most reliable brand, I’d rather get the best than take chances. 

 

 

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Congratulations on getting your boat! 😀 Keeping the bilge clean and oil free would help reduce the risk of the switch sticking. The grease from a conventional stern gland seems to be the main culprit, if the engine is in a separate bunded area, as it should be for the BSS. I've seen an old kitchen sieve hung below the gland to catch a lot of the grease be effective in keeping the bilge cleaner. It lets water through, but holds a lot of the grease in horrible gungy blobs on the mesh. Don't have this problem as my boat has a Volvo gland and stays dry. It still has a bilge pump, but uses a cheap float switch via a relay for auto switching, just in case the gland, or weed hatch fails, or any other reason for water getting in. It gets tested by hand every so often to check it still starts the pump.

A lot of what you are paying for in a proper float switch is the ability to handle the relatively high current that a bilge pump takes.

Jen

Edited by Jen-in-Wellies
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20 minutes ago, Withywindle said:

My wife and I are now proud owners of our first boat, a 15 year old Colecraft narrowboat. 

 

One of the comparatively few recommendations made by our surveyor was to fit an automatic float switch in the circuit to our bilge pump. This seems sensible and I was intending to go ahead, particularly as our boat will spend her winter on a marina and we will not be able to visit as often as perhaps we’d like, to check on her. 

 

Having said all of this, my research into suitable float switches has thrown up a few unexpected horror stories. These mainly involve them activating and getting stuck ‘on’ then burning out the bilge pump or running down batteries. One particular brand, Attwood, seems to come in for a lot of criticism in this regard. 

 

What are people’s thoughts on automatic float switches - a good idea or not? If so what is the most reliable brand, I’d rather get the best than take chances. 

 

 

They all seem to suffer due to the working environment in a wet greasy bilge.  If you have a greaser type stern gland I would advise siting the pump well away from it as the grease jams up the float.  The type without a float seem to rely on electronics to switch the motor, probably not a good idea in the bilge?

Most that I have seen that have not worked when needed are badly wired with poor cable, corroded joints, or not directly connected to the batteries and "someone" turned off the isolator!

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Automatic bilge pumps have en known to flatten batteries when they go wrong. As long as the stern gland has been properly adjusted and greased, then as long as you either live on the boat or visit every month/6 weeks you really don't need an automatic pump, but you will get water in the bilge. Even when a cockpit drain pipe through the uxter plate rusted through, the leaks did not come over the engine tray over a month - it probably would have got worse if I had not been regularly checking the bilge and finding the reason for the extra water.

 

If you feel that you must have an auto pump, make sure you fit a three position switch so you can turn the auto part off if you need to.

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9 minutes ago, wergie said:

Johnson make a submersible bilge pump that can be operated with a solid state level detection device, so no moving parts, but they ain't a cheap option

The Johnson switch also will not work when required as the enclosure is not waterproof. I have a collection of failed switches from the bilge and grey water tank. Seemed a good idea when fitting out.

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Thanks for all the very quick replies. 

 

My boat was owned by a former marine engineer and his maintenance regime was meticulous. 

 

The bilge and engine area is pristine. He was in the habit of putting a jug under the stern gland and emptying it regularly so no water ever collected in the rear bilge area. I’ve continued to do this, so any water that did find its way into the bilge while I was away from the boat over the winter would be relatively clean. 

 

I certainly would keep the manual switch option option either by fitting a three position switch or more likely a completely separate switch for the automatic option which may turn out to be more practical in my particular boat given the current switch layout. 

 

Still waying things up I must admit. 🤔

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3 hours ago, Tony Brooks said:

Automatic bilge pumps have en known to flatten batteries when they go wrong. As long as the stern gland has been properly adjusted and greased, then as long as you either live on the boat or visit every month/6 weeks you really don't need an automatic pump, but you will get water in the bilge. Even when a cockpit drain pipe through the uxter plate rusted through, the leaks did not come over the engine tray over a month - it probably would have got worse if I had not been regularly checking the bilge and finding the reason for the extra water.

 

If you feel that you must have an auto pump, make sure you fit a three position switch so you can turn the auto part off if you need to.

Many years ago it was pointed out to me that one good reason for fitting a three position switch was so that the bilge pump could be manually operated on a regular basis to stop it sticking through lack of use. I believe that in most hire boat yards, operating the manual bilge pump switch is part of the weekly turn round regime.

 

I have had a bilge pump stick through lack of use (and forgetting to operate the manual override switch on a regular basis) and it required dismantling and a good clean of its internals (which were predominantly stainless steel) before it wanted to go again! It was the motor internals that were the worst offenders.

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Move on board, and sleep with one arm hanging over the side of the bed so you can feel the rising water.

 

Alternatively sew a cat bell to each of your slippers.  The tinkling will wake you as they float around your cabin bumping into things.

 

Stoke your stove up high before going to bed and get in the habit of waking if you dream about being trapped in a steam drenched Turkish Bath.

 

Keep all your wire brushes in the middle of your bed, and sleep on the very edge.  That way if your boat starts to lean over you'll either fall to the soggy floor or roll the other way onto the brushes.  You can make it more interesting by betting which way you'll go tonight.

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I've always used auto bilge pumps with a manual option,  and all three times the boat got a leak the auto option has failed. It's good to have  but don't rely on it.

If the boat has a cruiser stern, it's going to get water in the bilge, I assume trad ones don't suffer as much. If cruiser, and the boat will be left unattended for months, I'd invest in a seriously good back deck covering.

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35 minutes ago, zenataomm said:

Move on board, and sleep with one arm hanging over the side of the bed so you can feel the rising water.

 

Alternatively sew a cat bell to each of your slippers.  The tinkling will wake you as they float around your cabin bumping into things.

 

Stoke your stove up high before going to bed and get in the habit of waking if you dream about being trapped in a steam drenched Turkish Bath.

 

Keep all your wire brushes in the middle of your bed, and sleep on the very edge.  That way if your boat starts to lean over you'll either fall to the soggy floor or roll the other way onto the brushes.  You can make it more interesting by betting which way you'll go tonight.

You don't have a wooden bottomed boat do you - your approach looks horribly familiar...!

 

Alec

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I've got a rule bilge pump and float switch, located in the area behind the engine bunded area. The stern gland greaser is tightened whenever I leave the boat and neither water or grease from the gland has ever been an issue. I also check the float switch is working OK whenever I leave the boat. I am semi-trad with a pram so rarely find any water in the bilge.   

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11 minutes ago, MartynG said:

Would it be preferable to let the boat sink?

Should bilges ot be dry except exceptionally?

 

 

Personally, I would rather have the level switch with the risk of flat leisure batteries than not have it with the certainty that the boat would sink if water starts coming in.

 

Whether the bilges stay dry does depend to an extent on the design, and even the detailing. A trad stern with a fully welded counter deck should stay dry. Add access to the weed hatch and there is now an ingress point. If arranged so that there is no connection between the counter and the rest of the cabin then only the counter would fill up but if not separated by a bulkhead there will be some ingress. If you have wooden cants at the bow or stern then they are normally bolted through which means holes and a bit of water creeping in. If you weld studs on instead then no holes, but it's more effort so less likely to happen on a boat built to a budget. There are various other details around the foredeck and whether it has a well and how that drains which can determine whether you get a perfect seal or not.

 

Alec

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Just now, MartynG said:

Would it be preferable to let the boat sink?

Should bilges ot be dry except exceptionally?

 

 

Absolutely this^^^^^^^^. Water does come in from the stern gland and other areas also condensation will deposit water. Obviously the best way is to check it on a daily basis. If you cannot then the next best thing is an automatic bilge pump. They are all junk, partly because they are all made in China and partly because of where they are situated. But if your boat isn't checked regularly and the pump packs up for whatever reason your boat could sink. Dead batteries or a burnt out bilge pump are not the end of the world, a sunken boat could well be. Boat ownership, just like house ownership, is a risky business. The big difference between a house and a boat is that a boat tends to be left for long periods of time without anyone checking it. IMO even with all the potentail problems that an automatic bilge pump has having one far outweighs not having one. 

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4 hours ago, ditchcrawler said:

But what is the power drain if powered up 24/7 and the boat not used

Nothing on the manual or on their website. The Johnson bilge alarm using the same sensor says "passive amps" 16mA so I guess the switch is probably the same. 

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1 hour ago, agg221 said:

You don't have a wooden bottomed boat do you - your approach looks horribly familiar...!

 

Alec

Rumbled!

I used to own a pair of composite Small Woolwich.  Both were steel rivetted sides with vegetable bottoms.

 

A friend had a Town Class motor and became adept at making Araldite go off under water at 3.15 am.

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5 minutes ago, zenataomm said:

Rumbled!

I used to own a pair of composite Small Woolwich.  Both were steel rivetted sides with vegetable bottoms.

 

A friend had a Town Class motor and became adept at making Araldite go off under water at 3.15 am.

Thought so! I used to co-own Hagley.

 

To the OP: avoid wooden boats (I only wish I could take my own advice as I still have Samson)!

 

Alec

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'Rule' are a respected brand in this field.

 

We isolate our batteries on leaving, and dont have much issue, but there are other options available, such as having more than one pump and switch, running off more than one battery system, and or dedicated batteries for the pumps as for other domestic use and or starting. 

 

You can also get/make counters which tell you how many times the pump has activated, as well as systems which spot a stuck switch...   ..and radio you to say so!

 

 

Daniel

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Some rather alarmist views here! A modern all steelnarrow boat is not going to leak canal water in except perhaps small quantities through the stern gland. Condensation can be very annoying, but the actual quantity of water is trivial compared with that necessary to sink a boat.  Poorly detailed (or maintained) cruiser stern drainage arrangements are likely to be the biggest source of water, but even if your pram hood or tonneau cover is carried off by the wind, you aren't going to get enough rain water in to sink a boat within a month or two. And surely nobody leaves their boat uninspected for longer than that!

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2 hours ago, David Mack said:

Some rather alarmist views here! A modern all steelnarrow boat is not going to leak canal water in except perhaps small quantities through the stern gland. Condensation can be very annoying, but the actual quantity of water is trivial compared with that necessary to sink a boat.  Poorly detailed (or maintained) cruiser stern drainage arrangements are likely to be the biggest source of water, but even if your pram hood or tonneau cover is carried off by the wind, you aren't going to get enough rain water in to sink a boat within a month or two. And surely nobody leaves their boat uninspected for longer than that!

That is what I tried to say. More surveyor  bullshine to justify their charge.

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14 hours ago, David Mack said:

A modern all steel narrow boat is not going to leak canal water in except perhaps small quantities through the stern gland. Condensation can be very annoying, but the actual quantity of water is trivial compared with that necessary to sink a boat.  Poorly detailed (or maintained) cruiser stern drainage arrangements are likely to be the biggest source of water, but even if your pram hood or tonneau cover is carried off by the wind, you aren't going to get enough rain water in to sink a boat within a month or two. And surely nobody leaves their boat uninspected for longer than that!

There is a lot of truth in this, including the fact most of the water will usually be rain! We tape over our back deck hatch over winter.

 

We have also tweaked the bilge arrangements so the 'cabin' drains into little accessible pockets under the back deck, but has a 2" bulkhead between that and the rear bilge compartment under the back deck (what would be a cruiser stern, but we have a folding wheelhouse) so that area, which can be painted readly, can get wet without getting the inaccessible bilge space wet. Obviously on a modern boat with underfloor engine, this area would have to be compartmentalised anyway due to the engine.

 

 

Daniel

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