Best Bilge Pump?

[AlastairLC]

This little baby looks like it might be what I’m looking for:
Rule 500 GPH 25SA Electronic Sensing Bilge Pump-500 https://www.amazon.com/dp/B01LZSYF42/ref=cm_sw_r_cp_tai_NcIoEb9D4YVCE
Any comments, positive or negative, greatly appreciated.

 

[dlochner]

While I'm sure it's a good switch, the inclusion of these wading shoes on the same page just doesn't inspire confidence.

View attachment 174698

I take no responsibility for Amazon's algorithms.

 

[dlochner]

This little baby looks like it might be what I’m looking for:
Rule 500 GPH 25SA Electronic Sensing Bilge Pump-500 https://www.amazon.com/dp/B01LZSYF42/ref=cm_sw_r_cp_tai_NcIoEb9D4YVCE
Any comments, positive or negative, greatly appreciated.

When Rule and others rate their pumps they are rated at zero head. Basically, just pumping water in a straight line and not lifting it from the bilge and out the side of the boat. Real life performance varies and the higher the pump has to lift the water, the lower the output would be.

Marketing, marketing, marketing.

 

[Maine Sail]

So what does ABYC say about manual pumps?

dj

The ABYC standards are for "electric bilge pumps". The part that pertains to this question below:

"22.8.6 The discharge location shall be above the maximum heeled waterline, or
22.8.7 the discharge may be located below the maximum heeled waterline if the discharge line is provided with both of the following:
22.8.7.1 a seacock installed in accordance with the requirements of ABYC H-27, Seacocks, Thru-Hull Connections, and Drain Plugs, and
22.8.7.2 a vented loop or other means to prevent siphoning into the boat. A check valve shall not be used for this purpose."


We suggest to all of our customers, who wish to DIY, to join the ABYC. You'll then have access to all the standards.

https://abycinc.org/mpage/becomeamember

 

[Maine Sail]

When Rule and others rate their pumps they are rated at zero head. Basically, just pumping water in a straight line and not lifting it from the bilge and out the side of the boat. Real life performance varies and the higher the pump has to lift the water, the lower the output would be.

Marketing, marketing, marketing.

They are also rated at charge level voltages... Sooooo much bovine dung in the world of bilge pump marketing it's scary...

 

[Jim26m]

22.8.7.2 a vented loop or other means to prevent siphoning into the boat. A check valve shall not be used for this purpose."

Typical code language. A vented loop is ok. "Other means" are ok, as long as it's NOT a check valve. Where do we find the installation guide for "other means"?

Take-away: According to ABYC, even the diaphragm pumps with integral check valves require a vented loop if the discharge is submerged at max heel (whatever max heel is...). I actually agree that a vented loop is more reliable than even the most reliable check valve.

I share your disdain for bilge pump tech info. It's very hard to tell what you're getting until you install and test it (preferably through several cycles).

 

[Maine Sail]

Typical code language. A vented loop is ok. "Other means" are ok, as long as it's NOT a check valve. Where do we find the installation guide for "other means"?

Take-away: According to ABYC, even the diaphragm pumps with integral check valves require a vented loop if the discharge is submerged at max heel (whatever max heel is...). I actually agree that a vented loop is more reliable than even the most reliable check valve.

I share your disdain for bilge pump tech info. It's very hard to tell what you're getting until you install and test it (preferably through several cycles).

Other means could be just a "high loop" but it may not ensure that the system won't back siphon if the discharge is below water. "Other means" can also mean stuff a small boat-owner would never dream exists, such as electronically actuated valves driven by angle sensors. This type of technology exists on larger vessels.

If the discharge is below water, at max angles of heel, a seacock is required as well as a vented loop or even a high loop. A vacuum breaker or siphon break is the preferred method as well as an outlet that does not get submerged. A check-valve should not be relied on to prevent back draining, good system design and installation are required.

When in doubt stick with the first line: "22.8.6 The discharge location shall be above the maximum heeled waterline"

"22.4.8 Maximum Heeled Waterline - the level of the water on the hull when the hull is inclined to
22.4.8.1 an angle of 7°, for powerboats, or
22.4.8.2 the level of the sheer amidships, for sailboats."

If the bilge discharge is dipping below water, the bilge pump outlet should be moved or a vented-loop/siphon break and seacock should be installed..

 

[Jim26m]

Thanks for the clarification! Is it just me, or would that waterline be difficult to determine when on stands or in the slings? Other than at or near amidships, that-is.

Absolutely agree with your points, just noodling through what the average DIY would do, hole saw in-hand, while his boat is hanging in the slings...

 

[dlochner]

Thanks for the clarification! Is it just me, or would that waterline be difficult to determine when on stands or in the slings? Other than at or near amidships, that-is.

Absolutely agree with your points, just noodling through what the average DIY would do, hole saw in-hand, while his boat is hanging in the slings...

Estimate the maximum heel angle the boat would have. Say 45° from the waterline at the middle of the transom, draw line at 45° to the port and starboard, making a large V. That will give you a good idea of what the waterline will be.

When I installed a vented loop on my head intake (between the pump and the bowl) I placed the Vent so that it was above the rail, knowing that at the maximum heel it would be above the waterline.

 

[JamesG161]

If the bilge discharge is dipping below water, the bilge pump outlet should be moved or a vented-loop/siphon break and seacock should be installed..

Never put a seacock on the bilge pump discharge. A good way to forget it when in berth.
Jim...

 

[robstart]

Look at amazon .
1. JABSCO 36680-2000 PAR Belt Drive Bilge pump 330 GPH, 12V, 10 Amp
2. JABSCO 36600-0000 PAR Belt Drive Bilge pump 480 GPH, 12 V, 10 Amp

 

[SG]

The loop needs a vacuum breaker (vented loop) or you can siphon water bit the boat.

The submersible pumps are the least expensive and generally highest capcit for the $’s. They are not positive displace this pumps, and essentially push the water out until the water at or ver close to the level of the pump. These pumps don’t push air enough to force water out of the hose very far “up”. So when the pump goes off, the remaining water simply runs back downhill. The check valve (at least for a while) keeps the water in the hose

ifyou have an “old” PAR style or other remote positive fisplacement pump, they do a little better at leaving less water in the hose to leak back. However, they are a lot more expensive, tend to wear out more often, and the rebuild kits are ridiculously expensive. They are essential if you have a narrow bilge which won’t take a larger enough diameter submersible.

 

[AlastairLC]

Thanks for all your helpful comments everyone.
I ended up getting this one:
Rule 1100 GPH 27SA Electronic Sensing Bilge Pump-1100 https://www.amazon.com/dp/B01LZT149C/ref=cm_sw_r_cp_tai_Mc1pEbNEHNVXQ
I’ll let you know how it works out.

 

[robstart]

Hey AlastairLC.
Look at Amazon: 1. Jabsco 36680-2000 Marine PAR, Belt drive Bilge pump 330 GPH, 12V, 10 Amp.
2. Jabsco 36600-0000 ...........................................................480 GPH

 

[Jim26m]

Thanks for all your helpful comments everyone.
I ended up getting this one:
Rule 1100 GPH 27SA Electronic Sensing Bilge Pump-1100 https://www.amazon.com/dp/B01LZT149C/ref=cm_sw_r_cp_tai_Mc1pEbNEHNVXQ
I’ll let you know how it works out.

Anxious to hear your feedback. Looks like they may have cured the airlock issue. Also, notice that they changed the rating voltage down to 12. I guess @Maine Sail must not be alone in complaining about the bogus rating voltage... although, they appear to be spinning it as an efficiency improvement rather than the outright misinformation it was. Love those marketing and pr folks.

Still hard to find pump performance data for it though.

EDIT: Oops. Maybe not. The manual still shows performance ratings at 13.6v (limited to free flow and 2 head points).

https://www.xylem.com/siteassets/brand/jabsco/fully-automatic-bilge-pump---technical-data-sheet---multilingual.pdf

 

[FastOlson]

Remember that the basic design of a centrifugal pump is the problem.
Trouble obtaining and holding 'prime'. Back-flooding and syphoning... which leads to additional trouble-prone 'solutions'.

Changing details of their marketing verbiage cannot overcome this limitation. They sell to boaters concerned with price alone.
While I have used centrifugal pumps for high capacity water movement (2" Honda gas powered, and 6" and 8" diesel power in mobile dredges), the small ones for boaters are seldom a good choice.

As always, your decision your boat. But be informed about the risks.

Moreover: last time I read of a real world test of pumps by Practical Sailor, the measured output capacity was a fraction of the advertised number on the box. You have to consider real hose runs, actual battery voltage of maybe 12.4, normal height of 'head' or lift, and types of hoses -- lots of boats have cheap ribbed hose. Note the numbers in the right hand column in the chart... and that's the theoretical best result from the vendor/marketing department, and still at 13.6 volts. ( Yikes !)

 

[dlochner]

Moreover: last time I read of a real world test of pumps by Practical Sailor, the measured output capacity was a fraction of the advertised number on the box. You have to consider real hose runs, actual battery voltage of maybe 12.4, normal height of 'head' or lift, and types of hoses -- lots of boats have cheap ribbed hose. Note the numbers in the right hand column in the chart... and that's the theoretical best result from the vendor/marketing department, and still at 13.6 volts. ( Yikes !)

Don't believe the numbers on the box. However, if all pump manufacturers are using the measuring technique, i.e., 0 head at 13.6 volts in to a smooth bore hose, then we can be certain that a 500 gallon per hour pump will move less water than a 1000 gph pump. How much less is anybody's guess and really dependent on the boats design and pump installation and available current. It gets trickier if someone is being more realistic about the pump's output. A pump that rates at 500 gph at 12.5 will move more water at 12.5v than a pump rated at 500 gph at 13.6v.

 

[Benny17441]

Before we all go out on a tangent lets go back to basics or the root of the problem; how much water are you talking about that is backflowing into the bilge? I have never had a problematic amount of water being ingested through the bilge discharge line from heeling the boat. Water rushing over the surface of a small aperture tends to suck water out not push it in. In any instance once the boat rights itself the pump will discharge any water in excess of the normal flowback.

 

[AlastairLC]

It’s not a lot. 2-3” maybe. But I want my bilge dry. That way I can keep it clean.

 

[Jim26m]

Before we all go out on a tangent lets go back to basics or the root of the problem; how much water are you talking about that is backflowing into the bilge? I have never had a problematic amount of water being ingested through the bilge discharge line from heeling the boat. Water rushing over the surface of a small aperture tends to suck water out not push it in. In any instance once the boat rights itself the pump will discharge any water in excess of the normal flowback.

Depends on the length of the discharge hose, and whether there is a vented loop, and whether the discharge is below the waterline at the time the pump shuts off. Best case, the volume of the hose between the vented loop and pump outlet will all flow back into the bilge at pump shut down (centrifugal pump, no check valve).

If I get where you're going, you're spot on. Any more flow back than the hose volume would indicate back siphoning.

I assumed he was only seeing the hose volume coming back, which could be alarming if you weren't expecting it.