frequent and very short pump activation

[Insequent]

Rule make, or used to make, an "Automatic" bilge pump. They cycle on frequently and if sufficient resistance is encountered (ie a bunch of water to pump out) they would run. Otherwise they would turn off. In other words, the damn things short cycled continuously. They did not need a float switch, probably touted as an advantage. Their latest automatic models use an internal sensor rather than sensing for pumping resistance by starting up.

I had one, removed it from service in 2012 although still have it at home I think as an emergency spare. It drove me nuts at night when all else is very quiet. Maybe check you don't have one of those old style automatic ones? Someone may have installed it not realising it was "automatic" and fitted a float switch as well.....

It might be something like this:
https://escapingoutdoors.com.au/automatic-bilge-pump-24v-69-l-min-detail

 

[Nick F]

If cleaning all the gunk out doesn’t fix the problem, I’m thinking you need to mount the float switch a little bit higher. You could put some kind of spacer under it; I used a piece of an old plastic cutting board to raise mine up 3/4 inch or so. That will a llow a little bit of water to build up before the pump comes on, which should eliminate the rapid cycling.

I agree with SeaDog - what is happening is that the water in the hose loop (between the pump outlet and the thru-hull) flows back through the pump when the pump stops. Depending on the shape of your bilge, and the characteristics of your float switch, this flow-back may raise the water level enough to make the pump start again. It look like your pump is in a little "sump" which would make this easier to happen.

To fix this, you need to have a float switch with a greater "deadband". That is, a greater water level distance between the start level and the stop level. Or, alternatively, a flatter bilge, so that the flowback volume does not raise the bilge level so much.

Another possible fix would be to install a smaller diameter hose, which would reduce the volume of water in the loop. I do not recommend this because it will reduce the flowrate when pumping. Make sure that there is not unecessary length of hose in the hose loop.

DO NOT UNDER ANY CIRCUMSTANCES install a check (non-return) valve in the hose. These valves stick and can leave you with effectively no pump.

 

[paulga]

It could be the float is constantly held at the critical angle due to its relative height vs the pump intake and the height of the through hull

Any hint how to fix the spacer to the plastic tray?

If cleaning all the gunk out doesn’t fix the problem, I’m thinking you need to mount the float switch a little bit higher. You could put some kind of spacer under it; I used a piece of an old plastic cutting board to raise mine up 3/4 inch or so. That will allow a little bit of water to build up before the pump comes on, which should eliminate the rapid cycling.

 

[Bmarler]

I wonder what the other hose and switch are? Manual pump and bilge alarm maybe?
Anyway, there are bilge pump controllers are have an off delay on them to allow the pump to run longer to ensure better evacuation of the water, maybe that would be a good idea here. Turning on the manual function of the switch or holding the float up for another 45 seconds would show if that strategy could work.

 

[paulga]

I have watched all 3 bilge pumps on the boat, the engine room bilge pump is the only one that does this. It's a Rule 40a, which does not look like the automatic style, and is tested to be triggered by the float.

I could not get a lot of details from its manual are the float and "cylinder " screwed to the bottom, which is a plastic tray on my boat?

Rule make, or used to make, an "Automatic" bilge pump. They cycle on frequently and if sufficient resistance is encountered (ie a bunch of water to pump out) they would run. Otherwise they would turn off. In other words, the damn things short cycled continuously. They did not need a float switch, probably touted as an advantage. Their latest automatic models use an internal sensor rather than sensing for pumping resistance by starting up.

I had one, removed it from service in 2012 although still have it at home I think as an emergency spare. It drove me nuts at night when all else is very quiet. Maybe check you don't have one of those old style automatic ones? Someone may have installed it not realising it was "automatic" and fitted a float switch as well.....

It might be something like this:
https://escapingoutdoors.com.au/automatic-bilge-pump-24v-69-l-min-detail

 

[RT Firefly]

greetings,
Mr. p. Remove the offending float switch and put a level shim (1/2" ?) underneath it and re-mount. This should allow any backwash to remain in the bilge until level rises again.

 

[CharlieO.]

I have a pvc "tray" as you call it. Mounted to it I have 2 bilge pumps (one general 800gph and one high water 3700 GPH) and two float switches. One switch I have mounted 3/4 of an inch higher than the other to activate my high water bilge pump in case the other pump fails or can't keep up. You can just mount the spacer block onto that plastic tray you have with screws of the appropriate length.

 

[luna]

Perhaps there is some confusion going on here.

The Rule 40A is a float switch inside a removable rectangular housing. In your case this 40A float switch likely energizes an alarm or possibly another bilge pump used as a high water level pump. Note how the 40A is mounted higher than the Super Switch.

The Super Switch which is the float switch that has no housing, likely energizes the bilge pump that is connected to the 1 1/8" white discharge hose. To remove this Super Switch you need to unclip it from its base, which remains screwed to the plastic tray.

Here is the dope on your 2 switches, including how to test them.

https://pentairaes.com/media/docs/R02_R24_rule_pumps_0513.pdf

The bilge pump itself is the cylinder thing that your gloved hand is holding. To remove the pump there are 2 plastic (usually red in color) barbs, one just below your gloved thumb, the other 180º opposed. Push those 2 barbs in and the pump lifts straight up. You can usually do one at a time if you wiggle the pump a bit. The base of the pump, which is a strainer, stays fastened on the plastic tray.
Even though your pump may not be a Rule, most bilge pumps are removed the same way. Have a look at this.

https://pentairaes.com/media/docs/R02_R24_rule_pumps_0513.pdf

In order to lift the pump very far you will need to snip the wire ties, remove the plastic U shaped hose clamp that is fastened to the wall, or remove the Stainless hose clamp that connects the hose to the pump. Then remove the hose from the pump.
Put everything back in once you are done cleaning and testing.

You would be wise to determine what the other 2 hoses are for so that you can either remove them if they are redundant or test to ensure whatever there intended purpose is still works.

Finally you will need to determine if you want a dry bilge or will accept a couple of gallons of water sloshing around down there. For me, my bilges are dusty.

There are 2 ways to accomplish this, the best method is to stop the leaks. This can be very difficult and could be a lot of work, but it is still the best way.
The other way is to install a Dry Bilge system. For what they are they seem expensive at about $300.

Panbo (a reputable site) has put one together or about $50, here.

https://panbo.com/a-dry-bilge-for-50/

Good luck with whatever you do.

 

[luna]

That was dumb.

I attached the same URL twice.

Replace the first one regarding the switches, with this one.

https://ca.binnacle.com/pdf/Rule-a-Matic Float Switch Technical Datasheet.pdf

 

[Nick F]

I am curious to know what the other things in your bilge are. See arrows in attached pic.

1 White hose entering vertically.

2 Grey electrical cable going to something.

Is there another pump down below the one we can see?

 

[SeaDogAK]

Any hint how to fix the spacer to the plastic tray?

I just used some kind of glue/adhesive that works underwater, like Water-Weld.

 

[luna]

The vertical white hose is intriguing, another pump down lower is possible, although I don't see any wiring going down, perhaps a feed hose to another bilge pump that is mounted higher and is controlled by the 40A switch. If so, it should not be a typical centrifugal bilge pump as those generally need to be submerged.

The grey electrical cable appears to me to be a clear vinyl tube. It's only grey (dirty) for the first 5 or 6". The remnants of an old air activated bilge pump switch?

 

[twistedtree]

I have watched all 3 bilge pumps on the boat, the engine room bilge pump is the only one that does this. It's a Rule 40a, which does not look like the automatic style, and is tested to be triggered by the float.

I could not get a lot of details from its manual are the float and "cylinder " screwed to the bottom, which is a plastic tray on my boat?

How does water get into the plastic tray from the surrounding bilge area? If you are just pumping out the tray, it will empty fast, turn off the pump, but there is enough residual water in the hose to largely refill the tray when it flows back. The pump needs to be able to pump a sufficiently larger volume of water than the contents of the hose before the pump turns off, or it will short cycle, just as yours is. It may just be a matter of cleaning to allow bilge water to flow into the tray while the pump is pumping.


As an aside, where is the water coming from?

 

[Nick F]

How does water get into the plastic tray from the surrounding bilge area? If you are just pumping out the tray, it will empty fast, turn off the pump, but there is enough residual water in the hose to largely refill the tray when it flows back. The pump needs to be able to pump a sufficiently larger volume of water than the contents of the hose before the pump turns off, or it will short cycle, just as yours is. It may just be a matter of cleaning to allow bilge water to flow into the tray while the pump is pumping.

I agree with TwistedTree - this is the point I was also trying to make (#32).

 

[tpbrady]

The quick test to see if what Twisted Tree said is true is when the pump does this, manually turn the pump on for 30 secs or so which should get enough water overboard out of the hose so the pump won’t cycle.

 

[Delta Riverat]

The perfect solution to this is put a dry bilge into that dugout and move the high volume pump and switch to the top.

Dry bilge keeps the bilge dry and the high volume only works if there is a serious problem.

 

[luna]

How does water get into the plastic tray from the surrounding bilge area? If you are just pumping out the tray, it will empty fast, turn off the pump, but there is enough residual water in the hose to largely refill the tray when it flows back. The pump needs to be able to pump a sufficiently larger volume of water than the contents of the hose before the pump turns off, or it will short cycle, just as yours is. It may just be a matter of cleaning to allow bilge water to flow into the tray while the pump is pumping.


As an aside, where is the water coming from?

If you look closely at the gloved hand picture you may come to the conclusion, like I have, that the float switch, bilge pump and whatever it is that has the vinyl tubing going to it is not on a tray (there is no lip) but is on a flat plate.

That does not mean the switch and pump can't short cycle, but does mean you can't fill the tray.

 

[paulga]

Running longer does not get more water out. The water level in my photo is the limit the pump can do

The quick test to see if what Twisted Tree said is true is when the pump does this, manually turn the pump on for 30 secs or so which should get enough water overboard out of the hose so the pump won’t cycle.

 

[paulga]

Thanks for your explanation
Tonight I only heard it 3 or 4 times, so if it's working I'm not going to do more testing or replacement

The vertical white hose is galley water discharge

The thin vinyl tube is mysterious:

The vertical white hose is intriguing, another pump down lower is possible, although I don't see any wiring going down, perhaps a feed hose to another bilge pump that is mounted higher and is controlled by the 40A switch. If so, it should not be a typical centrifugal bilge pump as those generally need to be submerged.

The grey electrical cable appears to me to be a clear vinyl tube. It's only grey (dirty) for the first 5 or 6". The remnants of an old air activated bilge pump switch?

 

[paulga]

It's a metal plate， not a plastic tray

I cannot see it clearly how where are the float base screwed to the plate

How does water get into the plastic tray from the surrounding bilge area? If you are just pumping out the tray, it will empty fast, turn off the pump, but there is enough residual water in the hose to largely refill the tray when it flows back. The pump needs to be able to pump a sufficiently larger volume of water than the contents of the hose before the pump turns off, or it will short cycle, just as yours is. It may just be a matter of cleaning to allow bilge water to flow into the tray while the pump is pumping.


As an aside, where is the water coming from?

 

[paulga]

I thought that might be the first approach I would try..

Where to find such a shim? How can it be fixed to a metal plate?

greetings,
Mr. p. Remove the offending float switch and put a level shim (1/2" ?) underneath it and re-mount. This should allow any backwash to remain in the bilge until level rises again.

 

[paulga]

Tonight I noted the the stuffing box is dripping, one drop per 4 seconds.

I didn't notice it was dripping before. Maybe it was triggered by the engine test run somehow, then it led to the bilge pump phenomena

Is the dripping normal?

 

[Nick F]

OK - so, looking at the photos in Post 49, the vinyl tube goes to a "diaphragm switch" which is clearly visible in the middle photo. This is the same type of switch as mentioned as an "air bell" type by DeltaRiverRat in Post 20. The rising water pushes air up the tube which pushes on the diaphragm and actuates a switch (normally used to start a bilge pump).

These switches are commonly used in washing machines to detect the water level. They tend to be reliable and are sometimes used for bilge pumps.

This explains the vinyl tube. However, you might want to figure out if this switch still does something. Perhaps short (connect) together the contacts on the switch and see if anything happens (pump runs? alarm sounds?). Perhaps trace the wiring from the switch.

This may have nothing to do with your pump cycling but, IMO, it is good to understand the systems on your boat. Personally, if it does nothing, I would remove it.

 

[mvweebles]

Tonight I noted the the stuffing box is dripping, one drop per 4 seconds.

I didn't notice it was dripping before. Maybe it was triggered by the engine test run somehow, then it led to the bilge pump phenomena

Is the dripping normal?

Normal? Yes. Doesn't mean it should drip, but many do. And many boats have sunk at the slip as a result. At rest, stuffing boxes can usually be adjusted to not drop at all, or only occasionally.

Paul, with all due respect, you would be doing yourself a world of favors to find a handyman type who can assist you on-site. While stuffing box adjustment is typically well within the realm of many DIY boat owners, assumes some basic nechanical skills have been aquired along the way that I think you are only now discovering. Nothing wrong with that - we all have to start somewhere. I applaud you for jumping in. But without that foundation, you are really best suited to pay a bit of "tuition" to someone who can show you (vs internet help), especially with components intended to keep water on the outside.

Best success

Peter

 

[ABfish]

A wet-dry vacuum with a couple of extension tubes is your friend for sucking all of the water out of the bilge. Makes it much easier to work on the pump and switch.

 

[luna]

paulga.

The url in post #39 shows how to remove the switch from it's base, (likely by pinching the sides of the switch below the pivot point & lifting) thereby exposing the base's mounting fasteners, which understanding that this is a metal plate could very well be small bolts, that are commonly called Machine Screws. If so, there could be nuts on the underside of the plate that you would have to get to in order to remove and reinstall the base of the switch.
From there, fabricate your shim (say 3/4" thick as suggested in post #29 & #32) drill the holes and remount the switch base using the proper length fasteners.

Whether or not this scheme actually works relies entirely on if the volume of water in the top 3/4" of the new level, less the volume of water in the top 3/4" of the old level is enough to compensate for whatever volume of water from the discharge hose was causing the pump to short cycle.

From your pictures of your bilge, I have my doubts.

One thing is for sure, you will have 3/4" more water in your bilge, which to me is a step backwards.

 

[paulga]

i'm sitting at dinette this morning and only heard the short cycling twice. it's not as frequent as previously, and I think it might be results from the stuffing box dripping. I'll first get some help in adjusting the stuffing box, then come back to study the bilge pump if it still does the short cycling.

the depth of the pit is a challenge. I'd need place some wood block to raise the plate, disconnect the pump hose to be able to raise the base even higher and flip it over, to work on screws or drill holes.

or I may first try to place a 1/2" acrylic board under the float side of the metal plate, this would also raise the float a big higher.

paulga.

The url in post #39 shows how to remove the switch from it's base, (likely by pinching the sides of the switch below the pivot point & lifting) thereby exposing the base's mounting fasteners, which understanding that this is a metal plate could very well be small bolts, that are commonly called Machine Screws. If so, there could be nuts on the underside of the plate that you would have to get to in order to remove and reinstall the base of the switch.
From there, fabricate your shim (say 3/4" thick as suggested in post #29 & #32) drill the holes and remount the switch base using the proper length fasteners.

Whether or not this scheme actually works relies entirely on if the volume of water in the top 3/4" of the new level, less the volume of water in the top 3/4" of the old level is enough to compensate for whatever volume of water from the discharge hose was causing the pump to short cycle.

From your pictures of your bilge, I have my doubts.

One thing is for sure, you will have 3/4" more water in your bilge, which to me is a step backwards.

 

[Lou_tribal]

The vertical white hose is galley water discharge

Do you mean that water from galley goes in the bilge/pit through that white hose?

L

 

[paulga]

Galley water may be directly overboard via some through hull, the same as washing machine

The Vertical hose could be the last section of rain water channel?

Do you mean that water from galley goes in the bilge/pit through that white hose?

L

 

[sndbowen]

Backflow not closing

Backflow not closing properly and allowing fluids pumped out of the bilge (not overboard), but still in the hose to slowly leak back into the bilge.