Installing an Electric Bilge Pump

[Red_Dog]

A friend of mine has asked me to install an electric bilge pump for him. That in and of itself is not a problem for me. I can do that.

Currently he has a manual whaler-type bilge pump located in his aft lazarrette, I suggested, and he would like to, to keep the manual pump for redundancy. I've thinking of ways to do this without running a separate line for the electric pump.

If you have installed and electric pump, keeping your manual:
- Did you run a separate line?
- Or did you use a Y-gate and check valves to use the existing discharge line with a by-pass around the manual?

I'll be working on a diagram meantime and post it to show you what I'm thinking.

Thanks,
Alec

 

[FastOlson]

Separate hose and thruhull, always. Having a separate hand operated bilge pump is also an offshore racing "category one" requirement. Or boat came with a manual Whale ($$) pump by the helm station, as well as two electric diaphragm type bilge pumps.
Tell him to still keep a bucket handy... as a backup!

 

[dlochner]

A friend of mine has asked me to install an electric bilge pump for him. That in and of itself is not a problem for me. I can do that.

Currently he has a manual whaler-type bilge pump located in his aft lazarrette, I suggested, and he would like to, to keep the manual pump for redundancy. I've thinking of ways to do this without running a separate line for the electric pump.

If you have installed and electric pump, keeping your manual:
- Did you run a separate line?
- Or did you use a Y-gate and check valves to use the existing discharge line with a by-pass around the manual?

I'll be working on a diagram meantime and post it to show you what I'm thinking.

Thanks,
Alec

It is better to have separate discharges for each pump, although it can be done with one discharge.

If 2 pumps discharge into the same outlet, the electric pump will need a check valve, otherwise the hand pump will simply pump the water back into the bilge. Diaphragm pumps have integral check valves.

Check valves can be problematic in bilge pump plumbing because they are easily jammed either open or closed rendering them ineffective.

 

[kappykaplan]

I have two electric bilge pumps in my boat, each with their own dedicated discharge. It's the only safe way to go.

 

[Red_Dog]

It is better to have separate discharges for each pump, although it can be done with one discharge.

If 2 pumps discharge into the same outlet, the electric pump will need a check valve, otherwise the hand pump will simply pump the water back into the bilge. Diaphragm pumps have integral check valves.

Check valves can be problematic in bilge pump plumbing because they are easily jammed either open or closed rendering them ineffective.

I'm leery of cutting new holes if I don't have to. Jon's willing to do it. At least then it's his responsibility if his boat sinks. He is also having backwash issues on the suction side of his manual pump. There is a lift of, say, 2' that he just can't clear with the manual pump. The answer to that problem is to install a check valve in the suction side.

I do understand your concerns with check valves. As a fire protection engineer, I've install I don't know how many pumps (BIG pumps), swing checks, poppet style spring loaded backflow preventors and reduced pressure zone backflow preventors. If a check valve can screw up, I've dealt with it.

Conceptually, my thoughts run along these lines.
- Electric pump discharge to check valve to wye fitting.
- Open suction line to check valve, to wye fitting.
- Wye fitting to existing discharge line.
- Cut discharge line before manual pump, install wye gate vale.
- Wye gate to manual pump and bypass loop.
- Manual discharge and bypass loop to wye fitting.
- Wye fitting to existing overboard discharge.

The wye (waste) gate valve would be located in the lazarette easily accessible to switch from electric to manual. Putting a check valve before the wye fitting tying the electric pump and open suction would prevent the electric sucking water up only to discharge it through the open suction line. All valving and fittings are easily accessible for maintenance or replacement.

I'm not sure what types of check valves are available that are also suitable. I'm not keen on the diaphragm checks. I may end up going brass checks through a plumbing supply house.

Does this make sense to you?

 

[dlochner]

There is a lift of, say, 2' that he just can't clear with the manual pump. The answer to that problem is to install a check valve in the suction side.

Assuming this is a Whale diaphragm pump, there is a check valve on the inlet and out let side. If he is not getting suction in that pump, he needs to rebuild it.

The bellows in the pump does age and crack, this reduces its efficiency or ice forms in the bellows and cuts the bellows with the same effect. The aluminum body will corrode a little and the check valves with not fully seat so suction and efficiency is compromised.

So, before installing a whole new pump, remove the manual pump, probably 4 or 6 screws, open it up and clean and rebuild it. Rebuild kits are relatively inexpensive (certainly less than a whole new pump install) and the kits are readily available. The SBO store may have them and Defender has them.

Bilge pumps have 2 functions, to get rid of nuisance water in the bilge and to try and keep the boat afloat in an emergency. For small amounts of nuisance water, you system may work. However, in an emergency when keeping the boat afloat is paramount, the more complicated the system the more likely it will fail. Murphy loves a good catastrophe.

Rebuild the manual pump first, then see if the electric pump is necessary. The Sabre 30 I sailed for 15 years only had a manual pump and it was fine for removing nuisance water.

 

[Red_Dog]

Dave,

I will take this under advisement. I've texted Jon to say that I'm going to see what feed back I get through this afternoon and evening, and that I would speak with him tomorrow.

It's the advice of people like yourself, that I trust, that I throw these questions out there.

I mentioned that I was a fire protection engineer. I found it most useful to put my design in front of the the most junior designer and let the find my errors. It was amazing the errors they would find. Also, a good lesson for them.

 

[Jim26m]

I'm leery of cutting new holes if I don't have to. Jon's willing to do it. At least then it's his responsibility if his boat sinks. He is also having backwash issues on the suction side of his manual pump. There is a lift of, say, 2' that he just can't clear with the manual pump. The answer to that problem is to install a check valve in the suction side.

I do understand your concerns with check valves. As a fire protection engineer, I've install I don't know how many pumps (BIG pumps), swing checks, poppet style spring loaded backflow preventors and reduced pressure zone backflow preventors. If a check valve can screw up, I've dealt with it.

Conceptually, my thoughts run along these lines.
- Electric pump discharge to check valve to wye fitting.
- Open suction line to check valve, to wye fitting.
- Wye fitting to existing discharge line.
- Cut discharge line before manual pump, install wye gate vale.
- Wye gate to manual pump and bypass loop.
- Manual discharge and bypass loop to wye fitting.
- Wye fitting to existing overboard discharge.

The wye (waste) gate valve would be located in the lazarette easily accessible to switch from electric to manual. Putting a check valve before the wye fitting tying the electric pump and open suction would prevent the electric sucking water up only to discharge it through the open suction line. All valving and fittings are easily accessible for maintenance or replacement.
Does this make sense to you?

Need to post the diagram to clear the arrangement up. But, you should let the owner install a new proper thru-hull and provide a separate, fully redundant, bilge pump system. Cutting a hole above the max heel waterline for a bilge pump discharge should be a no brainer (and no-brainer is my field of expertise!).

These systems are supposed to be idiot proof, and what you are describing seems to require proper setting of a manual valve and proper operation of a check valve. In a crisis, who will be trying to figure out the manual valve position or troubleshoot it if there's a gummy bear stuck in the check valve?

You also need to specify what type of electric pump you are installing (positive displacement or centrifugal), as centrifugal pumps can be tougher to get right in retrofit situations (which you probably already know). In any event, it would add to the exchange.

I'm no @dlochner , but my wife did make me stay at the holiday inn last night...

 

[dlochner]

I'm no @dlochner , but my wife did make me stay at the holiday inn last night...

I'm not quite sure how to respond to this.

We prefer Hiltons and boutique hotels.

 

[Jim26m]

I'm not quite sure how to respond to this.

We prefer Hiltons and boutique hotels.

I was channeling the old TV ad that use to elevate Joe Nobody to superhero status just because he stayed in their hotel the night before... You were the real superhero and I was playing the twisted part of Joe Nobody... they made several versions. Here's one.

 

[dlochner]

I was channeling the old TV ad that use to elevate Joe Nobody to superhero status just because he stayed in their hotel the night before... You were the real superhero and I was playing the twisted part of Joe Nobody... they made several versions. Here's one.

Yes, I remember those questions. But I won't claim any super powers except for learning from the many stupid things I've done.

 

[Red_Dog]

While I have stayed at a Holiday Inn, just not last night.

I am trying to advice Jon has to how go best about this. The system I proposed is a no brainier for me, Then again, this is the sort of thing that I would do automatically.

I should say, I've only had one indecent when a double check RPZ backflow preventor (or any check valve) went bad on me. It was a nightmare. All because the underground contractor did not properly flush the underground piping before I (Old Faithful Fire Sprinkler connected to it). 6" of water flooded the entire new building before I dug out a gallon of stone preventing the first check valve to shut.

 

[dlochner]

The issue with check valves in bilge pump systems is gravity. Stuff ends up in the bilge and then gets sucked up and pumped through the check valve and gets stuck preventing the valve from fully closing or opening.

My boat does have a single discharge outlet. There is a check valve on the centrifigual pump, an integral check valve on the electric diaphragm pump and integral check valves in the manual (Whale) diaphragm pump. The 3 pumps all discharge at the top of a loop before emptying out the discharge outlet.

With that said, I think the problem you're describing is due to aging bellows and rubber check valves in the manual pump. An electric pump is not a solution to that problem and may give a false sense of security, "if the electric pump fails, I have this manual pump." The only caveat about the manual pump and rebuilding is to practice your boat yoga first and make sure you have some band-aids handy. After all this is a boat project.

 

[Tally Ho]

A friend of mine has asked me to install an electric bilge pump for him. That in and of itself is not a problem for me. I can do that.

Currently he has a manual whaler-type bilge pump located in his aft lazarrette, I suggested, and he would like to, to keep the manual pump for redundancy. I've thinking of ways to do this without running a separate line for the electric pump.

If you have installed and electric pump, keeping your manual:
- Did you run a separate line?
- Or did you use a Y-gate and check valves to use the existing discharge line with a by-pass around the manual?

I'll be working on a diagram meantime and post it to show you what I'm thinking.

Thanks,
Alec

I have both a whaler manual pump (operates from my cockpit) and an electric pump.
as has been stated, both should have their own hoses and thru hull. That is the way my boat is set up.

Greg

 

[Red_Dog]

The issue with check valves in bilge pump systems is gravity. Stuff ends up in the bilge and then gets sucked up and pumped through the check valve and gets stuck preventing the valve from fully closing or opening.

My boat does have a single discharge outlet. There is a check valve on the centrifigual pump, an integral check valve on the electric diaphragm pump and integral check valves in the manual (Whale) diaphragm pump. The 3 pumps all discharge at the top of a loop before emptying out the discharge outlet.

With that said, I think the problem you're describing is due to aging bellows and rubber check valves in the manual pump. An electric pump is not a solution to that problem and may give a false sense of security, "if the electric pump fails, I have this manual pump." The only caveat about the manual pump and rebuilding is to practice your boat yoga first and make sure you have some band-aids handy. After all this is a boat project.


View attachment 183752

Oh, I understand. I believe what Jon wants is an electric pump to dump his bilge automatically when he is away from the boat. Further, He wants the convenience of dumping nuisance water withe the flip of a switch manually when he's on the boat; and automatically when on the boat. (I've recommended going with an automatic/off/manual switch separately fused and connected directly to battery 1.)

When I speak to Jon tomorrow, I will bring up the point that it's time to rebuild his manual pump. I'm also going to discuss running a separate discharge line into the lazarette, but still cutting in a wye fitting into the overboard discharge. That way we not going to add yet another bulkhead/thruhull fitting.

 

[Jim26m]

And to answer your original question, my electric pump system is totally separate. I tested it through 4 cycles after install to verify I hadn't caused an airlock issue with the discharge routing.

Something about installers putting pipe in trenches without plugging the ends... Drives engineers nuts! Chiller plants, potable water, fire water, raw water, heating water, all get cranky when they get started up full of mud and debris. Kinda like what winds up in a lot of bilges, though.

Good luck with the install!

 

[Benny17441]

Don't get rid of the manual gusher pump, that is for safety. The electric pump is just for convenience, to facilitate the removal of incidental water that copllects in the bilge. A scared person can discharge a large volume of water with the manual pump while the electric pump can only handle small amounts.

 

[Red_Dog]

The issue with check valves in bilge pump systems is gravity. Stuff ends up in the bilge and then gets sucked up and pumped through the check valve and gets stuck preventing the valve from fully closing or opening.

My boat does have a single discharge outlet. There is a check valve on the centrifigual pump, an integral check valve on the electric diaphragm pump and integral check valves in the manual (Whale) diaphragm pump. The 3 pumps all discharge at the top of a loop before emptying out the discharge outlet.

With that said, I think the problem you're describing is due to aging bellows and rubber check valves in the manual pump. An electric pump is not a solution to that problem and may give a false sense of security, "if the electric pump fails, I have this manual pump." The only caveat about the manual pump and rebuilding is to practice your boat yoga first and make sure you have some band-aids handy. After all this is a boat project.


View attachment 183752

I asked Jon about rebuilding his manual pump. He rebuilt it last year.

I have my doubts about getting a parallel line out of his bilge and into the the engine compartment; where then, I would options for running a new separate line for the electric pump.

This is the drawing I sent him to show what I believe are our options.

 

[odaydokay]

Separate discharge for sure is best. I set up the electric to pump relatively high reaching an installed Y in galley sink discharge location. I tried a check valve but was problematical. I found without it a bit comes back at shut off, bit not much. No discharged water gets into the sink, but every boat is different of course.

 

[Jim26m]

Option 2 needs a check valve in the manual pump bypass or the manual pump will just pump in a loop through the bypass, or suck air through the bypass and never prime...

Option 1: Why does he need the check in the manual pump suction? Seems like the manual pump would be self priming and internally checked. Are you worried about the manual pump internals failing? Just curious. I can see the need for that check in Option 2, however.