Bilge pump runs, but not moving water

[tkaustin]

2011, RT 25 SC.
We have a couple inches of water in the bilge, enough to cover the bilge pump. I can switch it on and hear it running but it does not move any water. Maybe a clogged intake filter?
I don't know the form factor of this pump. Is there a way to check an intake screen? I can't lift it up, it's securely in place for reason I can't see.

 

[4umfreak]

The pump is likely the 750 gph version of this pump.
Theory is you can remove it by twisting the top and lifting it straight out - if you have that much clearance down there!

 

[Newf]

That’s a Johnson pump and if you haven’t already done so you can start troubleshooting by removing the cartridge from the housing to see if the impeller is ok or if it’s plugged around the bottom of the housing with crap. You could also disconnect the discharge hose from the pump to check for anything plugging it. Not sure if you are aware but that little black box floating in the water is the auto sensor and attaches to a clip near the bottom of the housing of the pump. When water reaches a certain level on the sensor it kicks on automatically. Maybe you have it off for a reason.

 

[Newf]

Forgot to mention that to remove the pump cartridge you need to pry the little black horizontal tab, shown in the photo, out a bit in order to turn the cartridge and then lift it out. Tight area there but should be doable. Good luck.

 

[tkaustin]

2011, RT 25 SC.
We have a couple inches of water in the bilge, enough to cover the bilge pump. I can switch it on and hear it running but it does not move any water. Maybe a clogged intake filter?
I don't know the form factor of this pump. Is there a way to check an intake screen? I can't lift it up, it's securely in place for reason I can't see.

Update. I disconnected outlet hose at the one-way valve. Pump flows very nicely up to the one-way valve, but beyond the one-way valve the hose is plugged. I tried a garden hose with high pressure forcing water through either direction of that last segment of the output hose and could not get water to flow either way. My best guess is that over the summer some insects decided to build the nest probably with mud inside that pipe.

 

[tkaustin]

That’s a Johnson pump and if you haven’t already done so you can start troubleshooting by removing the cartridge from the housing to see if the impeller is ok or if it’s plugged around the bottom of the housing with crap. You could also disconnect the discharge hose from the pump to check for anything plugging it. Not sure if you are aware but that little black box floating in the water is the auto sensor and attaches to a clip near the bottom of the housing of the pump. When water reaches a certain level on the sensor it kicks on automatically. Maybe you have it off for a reason. View attachment 26348

It fell loose some time ago. I was expecting that it was a floating switch like my basement sump pump which floats free. I'll get it put back.

 

[Haifisch]

Did you try removing the check valve? Mine failed in the closed position. It's job is to keep water from flowing backward so it makes sense that you'd get no water from the garden hose on the outside. If the check valve failed closed, it probably wouldn't allow water from the garden hose any more than it would from the pump. To test, I replaced the check valve with a 1/2" barbed union. One I saw that water flowed I replaced the check valve and it is all good now.

 

[LMRanger]

The impeller is broken and the pump needs to be replaced.
It is soooooo much fun getting the old one out and the new one in. Done mine 3 times now.
And, that is the only pump that will fit under there.
I have looked at trying to find a pump I could mount out side of that spot and run a suction hose down but have had no luck finding one.

Ralph

 

[tkaustin]

Did you try removing the check valve? Mine failed in the closed position. It's job is to keep water from flowing backward so it makes sense that you'd get no water from the garden hose on the outside. If the check valve failed closed, it probably wouldn't allow water from the garden hose any more than it would from the pump. To test, I replaced the check valve with a 1/2" barbed union. One I saw that water flowed I replaced the check valve and it is all good now.

I disassemble the check valve and verified that water flows a very nicely from the pump to the open check valve. The blockage is from the check valve to the outside port. In the meantime I purchase a manual bilge pump and so I'm getting by with that.

 

[tkaustin]

The impeller is broken and the pump needs to be replaced.
It is soooooo much fun getting the old one out and the new one in. Done mine 3 times now.
And, that is the only pump that will fit under there.
I have looked at trying to find a pump I could mount out side of that spot and run a suction hose down but have had no luck finding one.

Ralph

After disassembling the check I determined that the pump works great. There is a blockage from the check valve to the exterior port.

 

[tkaustin]

Update. I disconnected outlet hose at the one-way valve. Pump flows very nicely up to the one-way valve, but beyond the one-way valve the hose is plugged. I tried a garden hose with high pressure forcing water through either direction of that last segment of the output hose and could not get water to flow either way. My best guess is that over the summer some insects decided to build the nest probably with mud inside that pipe.

Update 2, Final: clearing the section of pipe beyond the one way valve was pretty easy once I bought a skinny snake at the hardware store. It is a 1/8" by 10 feet snake in an easy to use container/reel. I pulled out muddy plant fibers reminiscent of solitary bee nests. The snake has kind of a corkscrew on the end and I pulled out half a dozen or so small clumps. Brief test bursts finally resulted in massive flow, like a garden hose.

 

[CaspersCruiser]

Thanks for the update. It will help others in the future who find this thread via a forum search.

I had a similar blockage in the hose for air conditioning water discharge. I was able to disconnect the hose from the thru-hull and clear the blockage by pulling out the nest using long-nose needle nose pliers. I will certainly keep the skinny snake in mind if any the thru-hulls become blocked.