Using a submersible for routine service in the Amel bilge would NOT be a good idea. What we call our “bilge" really is not a bilge in the traditional sense of the word. It is actually a grey water sump. Submersible centrifugal pumps would foul and fail in very short order. Submersible pumps can also cause all kinds of stray current problems that you really don’t want to deal with the consequences of. This would be one of those changes from the original Amel design you should just say “No” to.
It is very hard to find a 24 volt pump that is as suited to this service as the original that Amel selected. If you can find one it would be best. Really.
But if you can’t, there are good options...
There are only a few kinds of pumps available that will work as a grey water discharge pump on an Amel. Diaphragm pumps (like the original); some kinds of piston pumps; and possibly some flexible impeller pumps.
I worry that a flexible impeller pump would have trouble with the self-priming at the depth of the well, so I hesitate to recommend them.
Diaphragm pumps are good at pumping “dirty water”, but you need one that is very well designed to work for very long. Most mass-market marine pumps of this sort are designed for very infrequent service as shower sump pumps, and they are even short lived at that. Amel's pump is first-rate and has a long lasting diaphragm and check valves. There are others, like the line of pumps made by Bosworth that that seem very well made, but I have no experience with, and can’t comment on longevity.
One pump that would work well in this service is the T-series discharge pump by Sealand. They are robust, long lived, easy to care for, excellent at self-priming, no foot valve would be needed. This is a piston type pump, without the rubber diaphragm. Maintenance consists of changing check valves about every 6 months. These are made as raw sewage pumps. If a “chunk” can fit up the hose, they will pump it through. They can handle the “gunk”. BUT… the downside is they have lower capacity than the Amel original, and so will run longer on each discharge cycle.
Sealand also makes an “M” series pump of the same design, except with a bronze body that is much larger and has at least the capacity of the Amel original. Check hose sizes and space for this one to see if it is practical replacement.
I don’t have any interest in Sealand pumps, other than using one daily as a pump for un-macerated raw sewage for ten years with only routine maintenance. It just worked.
I have the good fortune that my boat came with a complete working spare of the original pump. Hopefully I can keep the original running for a long time yet.
SM #160, Harmonie
“Ships and men rot in port."
Danny , Yes my manual pump works great. My foot valve does not leak, at least while I am watching ,over a long time it may.I do not have the original pump , I have a Jabsco , which looks inferior to the original pump. I was wondering if anyone had installed a base and a submersible mounted perhaps a foot above the bottom , occassionally using the manual one to pump out the muck.
From: Danny and Yvonne SIMMS simms@...
To: amelyachtowners <amelyachtowners@...
Sent: Mon, Oct 17, 2016 2:05 pm
Subject: Re: [Amel Yacht Owners] Bilge / Sump pump
Try taking the suction pipe off the pump. Is it full? If not, fill it and see if it stays full. Of course if its not full the foot valve is leaking. The fill and watch will just confirm this.
I have the original pump. If the foot valve is working ie no leak allowing the water in the suction to go down at all, the pump is always full. I struggled trying to fix things at the pump. Now at last I have a foot valve that works and the pump does too. One thing I did was shorten the suction to get it higher above the sediment that gets into the sump and my problems have been much le ss since. Foot valves don't like bits of stuff stuck it them when they try to close.
However I wish it would self prime like the manual one does. It doesn't even have a foot valve and yet primes perfectly every time and it cheerfully pumps all the muck from the bottom.
Danny, As far as can determine the foot valve is not leaking, however over a long time it may . I have tried to seal and clamp the hoses as tight as possible. It has always been unreliable .
From: simms simms@...
To: Amel Owners <amelyachtowners@...
Sent: Sun, Oct 16, 2016 2:14 pm
Subject: RE: [Amel Yacht Owners] Bilge / Sump pump
Hi pat. I battled the bilge pump forever. The key is the foot valve. If you can stop that leaking so the pipe stays full you should have no more trouble. Also ensure there are no leeks in the suction pipe.
SM 299 ocean pearl
Sent from my Vodafone Smart
On Oct 17, 2016 2:44 AM, "sailw32@...
I have a Jabsco sump pump and have found it unreliable . The motor works fine , I have replaced everything and it still fails to pump water from the bilge every time. I have replaced the joker and flap valves and I have a check valve , but I think over time the pump slowly loses its prime and becomes air bound , when not used for some time. I have thought about buying a new one and hope it works better . I have looked everywhere and cannot find it . I assume all SMs have the same pump , can someone tell me where I can purchase a new one. Has anyone replaced it with something more reliable ?
Pat SM #123