Plumming a Sump Pump

[Bad Obsession]

Plumbing a Sump Pump

I need to add a sump into my Catalina 30. I have found a sump box that will fit in the bilge of my boat. I will have to move my float switch slightly but there is plenty of room and clearance to move it. When I put the sump box into the bilge I need to figure out a good way to attach it and after that I need to run a hose for the water to be pumped out with.

I was thinking about getting a Y section and running the sump pump out of the same line that the bilge pump goes out of. This would mean one less through hull, the bilge pump runs to the transom so no worrying about syphoning, and it would be a shorter distance to run it.

I know that a lot of sumps on Catalinas go into the sink drain/raw water intake for the head. I would have to add a one way valve into it and I am not crazy about this idea.

If I run the sump out of the line that the bilge runs out of I could put one way valves in the bilge line and the sump line before it goes to the Y section where the lines will spice and go to the transom.

Any thoughts or suggestions on this?

I am still trying to figure out why Catalina didn't have a sump installed when the boat left the dealership.

 

[Ron20324]

As I see on my neighbors C30, they did put in a sump- it's called a bilge, however.

 

[Bad Obsession]

That is what the original sump pump was in my boat! Ugh.

 

[Don S/V ILLusion]

One-way or backflow valves are not a wise thing to put anywhere in a boat and especially not in a bilge line. They can clog and you won't know until it is an emergency.
Without it, all you'd accomplish is backfilling the bilge with the sump water as the bilge is lower than your transom. Any of a number of alternatives are preferable, one of which is to eliminate the sump idea in favor of an auto switched pump which will sense water and discharge it without having to collect it in a sump - that is how Catalina does it in their current shower discharges.

 

[Chuckbear]

Putting a check valve in the bilge pump may not be a good idea since they have been known to interfere with the operation of the bilge pump.

 

[Ross]

A vented loop precludes back siphoning.

 

[Bad Obsession]

So it would be best to run the sump out of the back of the boat to its own through hull?

 

[Stu Jackson]

Is this for a shower sump?

Sure sounds like it. If it is, use the check valve between the sump and the diaphragm pump. You can pup it out of the head intake without a another valve. I wouldn't use the bilge pump line.

Two different things:

1. bilge pump from the sump

2. sump pump assembly in the bilge to pump out the shower.

The description of the system is how they did it on our C34, used the head sink thru hull.

 

[Don S/V ILLusion]

So it would be best to run the sump out of the back of the boat to its own through hull?

You don't really need a new separate thruhull but if that's your preference, I'd run it to a small thruhull above the water line, either on the transom or the topsides, as close to the location of pump as practical. This precludes having to install a loop to preclude backflow which also causes back=pressure on the pump. As others have pointed out, an existing thrhull from a sink drain would also work.

Sumps such as this will retain some water causing an additional maintenance task to avoid the smell and could be entirely avoided by a simple auto sensing pump which would simplify your install and also reduce cost.

 

[Benny]

I'm probably missing the point; the idea of a sump box and pump is to quickly evacuate water from a high flow unit (shower drain) to the main bilge to prevent the water collector (shower floor) from overflowing. A pump can push more water than gravity. Was the original setup not adequate or are you making a modification to enhance performance? The proper way would be to install a sump box with automatic pump under the sole next to the drain as the box can collect water and at a certain predetermined level it can trasfer the collected volume into the main bilge to ready itself to accept more. For obvious reasons the capacity of the sump pump should not exceed the capacity of the bilge pump. Connecting pumps in tandem and the use of backflow valves may create more problems than intending to resolve. Now if there is no space to place the sump box under the sole you may consider not using a box as there is really no reason for a sump inside a sump. There are available in the market water sensing electronic pumps which can be installed anywhere in the drain hose to speed up water flow to the bilge. Like I said perhaps I'm totally missing the point but in any instance I would recommend to keep it simple.

 

[Peggie Hall HeadMistress]

You are missing the point Benny

The purpose of a sump is to keep water OUT of the bilge by collecting it in a small box and pumping it overboard. The pump is typically a submersible sump pump with or without a float switch...if it has a float switch it will turn on automatically when the water in sump gets high enough...if it doesn't have a float switch, the user will need to turn it on when he starts his shower. Idieally the thru-hull should be above waterline, but can be below waterline if the necessary vented loops are installed in the sump discharge line.

If you're gonna dump the sump into the bilge, there's no point in having a sump...just let the shower drain into the bilge. However, most people aim to keep their bilges as dry as possible...so not only is a shower sump desirable, but most people also prefer to have their ice boxes drain into a sump instead of the bilge too....because shower and ice box drain water is full of bacteria, body oils, soap scum etc that, along with sea water, rain water and wash water, turn a wet bilge into a stinky primordial soup that can make a boat smell like a swamp or even a sewer.

 

[Rick Sylvester]

Shower drain

Some have alluded to a water sensing pump. This is what we do:

http://www.svanthem.com/Shower Sump.html

 

[seadaddler]

My shower

The way my shower works is no sump pump box just a pump with a on and off switch.
You take your shower and watch for the water in the pan and the switch is next to the shower so just turn on the switch and it the pumps it over board,works OK for me,comes from Hunter like that.
They Hunter just stopped using a sump box to clean,the pump looks like a wash down pump with a switch to turn on when needed.
Nick

 

[Bad Obsession]

I have a sump box that I was given that will fit into my bilge area. The original system was the shower drained through a tube into the bilge....nasty. I can hook that tube right to this sump box. I already have a pump for this box as well and all I need to do is replace the float switch.

If I run the sump's discharge line to the transom I don't need a vented loop and I have no real danger of syphoning.

Another thought is that if I do this and run the pump directly to the battery there is a secondary bilge pump in the boat. If the water in the bilge gets high enough to overflow the sump box the sump pump would kick on and keep the bilge from getting any higher should the first bilge pump fail.

Currently, my bilge can get nasty quick. I keep it clean but it still tends to get water in it. By taking the shower water out of the bilge it would solve that problem.

If I run the sump through the sink discharge line, which is a short distance, it would tripple the distance of the hose if I ran a vented loop. Wouldn't it be better to put a one way valve in the sump or is this not a good idea?

 

[Ron20324]

B/O, can you put a pump in the head area somewhere, run the shower drain right to it, then go overboard right there also? A toggle switch in the head allows a shower-er to pump as needed. Also good when cleaning the head and floor of the head. That's how my new Beneteau works. If your bilge is like JIMM's, it's about 8" wide, 8" high, and and about three feet long- where the keel bolts are?

The sump as a backup is a good idea, too. Can't have TOO many bilge pumps.

 

[Bad Obsession]

There is no area that is accessable under neath the floor of the head in the Catalina 30. The current shower set up drains from a drain in the shower through a hose that runs into the bilge of the boat. The bilge is about 10" deep by 5" wide. The keel bolts do attach in that area but there is plenty of room in there.

I would rather drain into the sump box that I was given that fits in my bilge area. I will mount that sump box in there and have that pump out somewhere. The main thing is trying to figure out where to drain it too....through hull in the stern which is a descent amount of distance to run the hose or have it drain through the sink. If it drained through the sink then it wouldn't be a good back-up bilge pump.

Damn thing with boats is that everything is a compromise.

 

[Stu Jackson]

If it drained through the sink then it wouldn't be a good back-up bilge pump.

Why the heck not? It's still going overboard. At least we guessed right about it being a shower sump. If it was my boat, I'd install a diaphragm pump, a vented loop and a check valve and drain it out your sink drain as I mentioned in my last post. This is what Catalina does on our boats. ou could use a pump inside the sump, as earlier mentioned.

I don't like the idea of the long hose to the transom, and disagree that that long hose doesn't need a vented loop. Ever power at high revs and have the stern squat? Ever been in following seas? Of course, I know you have, and that's why no vented loop on a line like that is asking for trouble, with a capital T.

 

[Bad Obsession]

I see what you are saying Stu...So I would run the hose from the pump inside of the sump box, underneath the shower floor, behind the sink and put a vented loop up there. Then from the vented loop go down to where the through hull is located and use a T fitting and add the sump into there.

For the wiring I should run the hot up to the fuse pannel that way and maybe link into the water pressure system?

 

[Stu Jackson]

Sounds good...

Yes for the hose concept. Think out the check valve, carefully. What you want to do is minimize the possible back flow from water after the pump getting back into and filling up the sump. Since our arrangement is different than yours, you'll have to decide.

Ours: shower drain, hose to sump, hose from sump to diaphragm pump with the check valve right before the pump, pump to hose with vented loop, hose to thru hull. Our hoses are very short, longest one is 2 1/2 feet from the sump box to the pump and pretty much the same up to and down from the vented loop. Yours MAY be longer - longer hose = more water to back down into the box.

Yours has the pump IN the sump it seems. So you have to think about whether you want the check valve before or after the sump pump. If it is before the pump, the open body of the bottom of pump (like traditional bilge pumps) lets water drain back, so it appears your check valve needs to go after the pump on the hose from the pump to the vented loop.

In your case, what matters is accessibility. Do NOT put the check valve where you can't get to it EASILY. Our check valve is right under the door under the head sink, and it's one of the easiest things to service on the whole boat! Yours can go right in the bilge, just next to the box, very handy.

SCREENS: Because there's a check valve, ya wanna make danged sure that hair, or at least as little as possible, goes down the drain. One of my colleagues came up with a great idea: get some plastic window screen material, preferably pretty fine mesh; put a dollop of silicone around the main drain and press a suitably sized piece of screening over it. When the screen gets clogged, either replace or clean it. You will NEED to do this to avoid crudding up your check valve.

WIRING: I'd keep it as simple as possible. It depends on the type of pump you have. If it's self starting, like a bilge pump with an internal float, you just need power and it should do the rest. What we have is also simple: sump pump on breaker panel, toggle switch in the head; to take shower - turn on breaker, use toggle switch to run pump; need to remember to manually run the pump or else folks outside say "Hey, your shower water and suds are all over the cabin sole, whaddya tryin' to clean for goodness sakes, you or the boat?" With a manual switch in the shower compartment, it only needs to be on when you're running water. When you shut the water off, say to lather up with soap, you can shut off the pump.

Another suggestion is to get an on-off shutoff type fitting right on your shower wand, which i assume is your head sink faucet. See: http://c34.org/bbs/index.php/topic,4174.msg23801.html#msg23801 It not only saves a lot of water, but keeps the temperature settings. A little drips out, it's not 100%, more like 99%. Works great.

Ideas about wiring were discussed in Peggie's earlier response; depends on what you do have.

 

[petersea]

Some sump boxes and pumps have a"check valve" of sorts built in already ( or at least mine does) If you take the pump out and look in the line there is a "duckbill" type check valve built in the overboard side of the pump ( in the plastic pipe from pump to side of box ). These sumps will need to be cleaned out periodically and have a strainer built in just for that reason,so if you put an additional check valve in check and clean it out every time you clean sump. Don't forget to winterize them if you are in cold country.