Bilge Running Randomly

[GreggL]

Every now and then my bilge will run for a few hours straight for no apparent reason. There's no water except a little bit in the out pump from the bilge seemingly stuck without enough power to be pushed through.
Will this cause it to run? If so, is there anything I can do to stop this from happening?
Thanks!

[Nemo55]

Without knowing the type of pump and how it is triggered,thats kinda hard to answer..

[ShaunJ]

I would check the float switch.

[ozskipper]

Yep, float switch is sticking. Imho

[belizesailor]

Which make & model of pump? The Rule fully automatics will do this and they are junk.

[GreggL]

Not sure the make and model as its placed pretty well out of reach and mostly out of sight. It is however a fully automatic one.

I checked the float switch and that seems to not be the issue.

When I pull the out hose off and drain the pipes it'll shut off. For some reason when the bilge fills up, the last bits of water don't make it all the way up the hose and get stuck in the last few inches. It seems this is the issue. Any thoughts?

[Blue Stocking]

Install a small secondary pump that can remove that final bit of water that is running back and causing the pump to cycle.
There is a strong contingent here that doesn't like non-return valves in the line, sometimes its the only answer--other than the former second pump idea.

[GreggL]

Originally Posted by Blue Stocking

Install a small secondary pump that can remove that final bit of water that is running back and causing the pump to cycle.
There is a strong contingent here that doesn't like non-return valves in the line, sometimes its the only answer--other than the former second pump idea.

Thanks! I'll look into that.

[S V Zydico]

Maybe a one way valve after the pump, we have had the same problem and it was syphoning in a seaway with a certain motion of the boat as our outlet is not to far above the waterline. Small pumps can't push a lot of positive head usually only half to two thirds of what is claimed at full pressure. With a small amount left in the line it airates the water can't pump
It out because it is not a solid body of water and will
tend to keep running because the switch is still being tripped. So a one way valve close to the pump should fix it. Mitch

[belizesailor]

Originally Posted by GreggL

Not sure the make and model as its placed pretty well out of reach and mostly out of sight. It is however a fully automatic one.

I checked the float switch and that seems to not be the issue.

When I pull the out hose off and drain the pipes it'll shut off. For some reason when the bilge fills up, the last bits of water don't make it all the way up the hose and get stuck in the last few inches. It seems this is the issue. Any thoughts?

If it has a float switch then it is not likely a fully automatic version (these have internal float switches or other mechanisms). Although I have wired a float switch to the fully automatics to temporarily work around their "behavioral" problems. The ones by Rule which use "water sensing" techniques rather than a physical switch are the worst.

I suggest you figure out how to gain access to your bilge pump or relocate it to where you can. Because they do require some maintenance such as cleaning the strainer. Which by the way, can also cause the symptoms you are experiencing. If the strainer is clogged with debri, and the float switch is in the "on" position, then the pump can run indefinately because it will move llittle or no water thus the water level will never drop and the float switch will stay in the "on" position or it will drop very slowly. This will probably result in a burnt out bilge pump (not all have thermal protection circuits)....then you will need to get at it to replace it...something you will need to do sooner or later anyway (probably sooner). So, get access to that bilge pump.

Avoid installing a check-valve if you can because they just create another point of failure. But, as pointed out by another poster, sometimes it is the only practical solution.

[S V Zydico]

Yes one way valves can give problems if debri gets caught in them but like anything the need checking occasionally but that's pretty simple. And a shut off valve on the outlet is totally necessary, specially in heavy conditions. We don't run auto pumps its against EPA regs in most states within a certain distance from the coast, so we have a bilge alarm and just turn the pump on manually when it is safe to do so. Mitch

[CarlF]

Inexpensive centrifugal bilge pumps (like the Rule but seems to be true of all brands) don't last long. A bilge is a hostile place. If the pump is more than two years old, I'd replace it first. There are two strategies that seem to have the happiest long term results.

a) Install a diaphragm pump like a Whale Gulper and a very long life switch like the Ultra
TEF-GEL - Ultra safety systems - Home page

b) Install a small inexpensive automatic pump and carry a spare. Attach the pump to a piece of plastic pipe that makes it easy to pull out for servicing. Assume you'll replace it every few years. Install a 2nd large pump on a platform about six inches higher that only gets wet in a flooding. Hopefully, this pump will never be used. Attach a really loud alarm to this pump.

I use "b" myself.

[svlamorocha]

Originally Posted by GreggL

f. For some reason when the bilge fills up, the last bits of water don't make it all the way up the hose and get stuck in the last few inches. It seems this is the issue. Any thoughts?

You may have "short cycling" if the volume of water contained in the hose in between the pump and the high point of the antisiphon loop (=volume of water that drops back into bilge when centrifugal pump turns off) is greater than the volume of water contained in the bilge between the height at which the switch turns on and the height at which the switch turns off.

If you want the forum to be most helpful you need to provide info about type of pump and float switch and the dimensions of the hose.

Cheers

C

[DeepFrz]

Mitch, a one way valve is not the way to solve a siphoning problem on a bilge pump. Sooner or later something will get caught in the valve (or the valve will fail) and you may lose your boat. The outlet hose should go up well above the heeled waterline and should have an anti siphon valve at the top of the loop. That is the only way to ensure you don't siphon in a boatload of water.