Macerator & Other Discharge Valves?

[Scott T-Bird]

Here's a couple of items you'll want to put at the top of your "TO DO" list.

Notice that the pump discharge hose is only a white, light duty vinyl hose:

View attachment 175885

This should be a heavy duty sewage hose or it will (or already has) started to smell really bad. Not a big deal if you have no sense of smell . Also, I notice the macerator discharge hose in your photo is now black. I would do a complete inspection from one end to the other just to make sure there are no surprises (or stinking nightmares) waiting for you.

The second item I see is that the PO has labelled the suction side of the pump as the discharge. Not entirely unexpected as all PO's are idiots, as I think most here will attest to.

The one bad item here is the the cheap plastic valve on the inlet to the pump. It is below the water line and so, is a bad idea if the through hull is open (and your is). Also, you never want a valve here as you will ultimately, at sometime in the future, run the pump for an extended period of time with the valve closed. This will burn out the pump shaft seal after a few minutes. For now, I would suggest wiring the valve open and leaving the macerator through hull closed until using it. Definitely not open as your photo shows.

Nothing life threatening here at this time. C'mon now, admit it, you were starting to run out of jobs to do on the boat and this just fills out the list nicely .

I think there may be some mis-information.

The small diameter white hose from the pump discharge looks like Shields Series 148 or something similar. While it may not be the most odor resistant, it certainly is suitable for the use. I'd rely on Peggie's assessment for this. The black corrugated in the last photo is certainly just a cover for the wiring. The white hose to the right side is probably unrelated to all of this. The intake would more accurately be called "suction" but the labeling clearly calls the valve out for "Macerator Discharge". That is how the system is used … it is a Macerator Discharge system from the holding tank, so I wouldn't find any fault in the labeling. It is NOT a discharge directly from the toilet. For that reason, I don't know why the valve would be a bad idea or an improper valve. Perhaps it is redundant assuming there is a y-valve in front of the macerator pump. You have to open the valve to pump out the holding tank to seawater discharge, which is probably an infrequent operation. The pump is below water line, but it is isolated from seawater on the intake side. I would certainly prefer double clamping but the discharge connection from the pump doesn't appear to have enough length for double clamping. It seems that you would need to rely on the thru-hull valve and double clamping at the thru-hull.

I would expect that there would be a y-valve in front of the macerator pump turned toward the pump out hose normally. I might be wrong about this.

In the previous photos, the labeling is above the thru-hulls. Both of the black corrugated hoses are for the sinks. We see the labeling for the macerator discharge, but we don't clearly see the thru-hull or the white discharge hose. The 2 sink thru hulls are open. The macerator discharge is closed, as it should be. I don't think there is anything uncommon about leaving the sink thru hulls open when the boat is occupied and closing them when leaving the boat. I certainly close my galley sink drain when I leave because it is below waterline, but I leave the vanity sink drain open because the thru hull is above water line.

 

[JRT]

@pumpkinpie is not on a lake, not sure why that assumption was made.

 

[Ralph Johnstone]

Many people on fresh water lakes and rivers have toilets designed to use pressurized water from the fresh water tank.

Are you saying that small "separate" fresh water tank is used exclusively to supply the head with pressurized water ? Seems redundant or I just don't read so good this early in the morning. If you could explain please ? ? ? ?

 

[Ralph Johnstone]

@pumpkinpie is not on a lake, not sure why that assumption was made.

Mea culpa !

I took that from your reply #10 and then proceeded to mix it up with PP's original post. I have got to stop posting before high noon.

 

[quadrille38]

Many people on fresh water lakes and rivers have toilets designed to use pressurized water from the fresh water tank. But if it's a sea water (designed to pull in water from the lake) toilet, it connecting it to the fresh water supply is a major no-no even with a backflow preventer installed and every toilet mfr specifically warns against it in their installation instructions.

--Peggie

Exactly, our boat is plumbed such that the pressurized system feeds the toilet. I know people question the use of fresh water for that but since we aren’t using lake water we don’t get algae and such In the holding tank. Reduces growth in the tank. And frankly it doesn’t use that much water for flushes.

I brought it up because pumpkinpie is a Hunter 38 like I am. Might be false assumption but I was thinking they were set up in a similar fashion as we are.

 

[quadrille38]

Are you saying that small "separate" fresh water tank is used exclusively to supply the head with pressurized water ? Seems redundant or I just don't read so good this early in the morning. If you could explain please ? ? ? ?

No it pulls off the main water tank. No separate tank

 

[Peggie Hall HeadMistress]

The small diameter white hose from the pump discharge looks like Shields Series 148 or something similar. While it may not be the most odor resistant, it certainly is suitable for the use. I'd rely on Peggie's assessment for this.

"Suitable" is a relative word. While #148 flex PVC is sanitation hose, making it arguably "suitable for the use," it's the LEAST odor resistant hose, actually suitable only for toilet intake and holding tank vent lines. It should never be used for any line that carries sewage, especially any in which sewage can sit, unless you want replace it frequently or live with a stinky boat. Boat builders use it because it's the cheapest...boat owners buy it for the same reason. Hose that has to be replaced fairly often isn't much of a bargain 'cuz buying it even twice and you've spent the price of hose that is odor permeation resistant.

--Peggie

 

[Peggie Hall HeadMistress]

Exactly, our boat is plumbed such that the pressurized system feeds the toilet.

Is your toilet one that's designed by the mfr to do that, or have you connected a sea water toilet to the fresh water plumbing? What's the make/model?

--Peggie

 

[quadrille38]

What's the make/model of your toilet? Is it one that's designed by the mfr to do that, or have you connected a sea water toilet to the fresh water plumbing?

--Peggie

I don’t recall the brand right off hand Peggie. I can check for you. We bought the boat new and it came plumbed that way. Not a custom job done by me. I didn’t mention but it’s a Great Lakes boat. And it’s not an unusual set up here.

The electrical system is set up to support that configuration in that the switch for the water pump has to be on to pressurize the water system and the switch for the head on too before it will flush.
In the head there are rocker switches and pushed in one direction fills the bowel with water and in the other direction drains the toilet. There is a grinding pump on the toilet that macerates and shoots the waste up into the holding tank.

 

[Ralph Johnstone]

No it pulls off the main water tank. No separate tank

Don't you still run the risk of having sewage backflow into your potable water ?

 

[Peggie Hall HeadMistress]

I don’t recall the brand right off hand Peggie. I can check for you.

Please do...but not for me, for YOU. Toilet parts aren't interchangeable between mfrs, and sooner or later you're gonna need to troubleshoot it.

Ralph, to answer your question: bowl contents won't backflow into the flush water intake fitting, but bacteria from the contents can...which is the reason why ONLY toilets that are designed to use pressurized fresh water should ever be connected to the fresh water plumbing.

--Peggie

 

[Scott B]

I have attached another photo that shows a different angle of the switch that looked like just a light. You can see there are three switches on the panel of the same type.

This boat was in such great condition when we purchased it and rarely used (10 years old now but the macerator pump works), so I don’t believe anything has been done aside from what was completed at the factory, however, I’ll definitely check it out. I’d rather prevent than fix a problem. Especially a stinky one.

On page 7.8 of your manual, it explains how to operate the macerator. The breaker switch ( line 3. ) on the left in your picture, supplies power and to protect the electrical in case of an overload. The second switch ( line 4.) on the right in your picture, operates the pump and has to be held on until the macerator empties the tank.

The white PVC hoses was standard install by Hunter for that era of boat. Ours is a '05 H33. I've now replaced all of the hoses. The waste hose permeated and was replaced a few years ago. I also removed the macerator as the pump was downhill from the tank and waste sat in the hose above the macerator and was very smelly. ( our boat will unlikely see ocean areas where the macerator can be used )

Check the ribbed hose that is the drain for the galley and head sinks. Mine had a small split right beside the black reinforcing and was difficult to see but would leak slightly when we drained the galley sink. I've now replaced all the drain hoses and the intake hose for the head.

The thru-hull valves lead directly overboard and should be closed when you're not on the boat. It keeps the valves operational and not sezing up and will stop a flood if one of the hoses give out as all of them are well below the waterline.

Do yu have a thru-hull next to the ones in your pic that is lablled head intake? If so then you have sea water flush for the head.

 

[quadrille38]

Please do...but not for me, for YOU. Toilet parts aren't interchangeable between mfrs, and sooner or later you're gonna need to troubleshoot it.

Ralph, to answer your question: bowl contents won't backflow into the flush water intake fitting, but bacteria from the contents can...which is the reason why ONLY toilets that are designed to use pressurized fresh water should ever be connected to the fresh water plumbing.

--Peggie

I pulled the manual out. It’s a Jabsco Model 37045-Series
The manual states it is specifically designed for use with a pressurized water system, either from the potable tank or from another system such as a wash down pump. It has an anti siphon valve in the water line.

 

[Peggie Hall HeadMistress]

If it's specifically designed for use with a pressurized water system, great! And you also have the owners manual for it...I'm impressed!

--Peggie

 

[Ralph Johnstone]

I pulled the manual out. It’s a Jabsco Model 37045-Series

Thanks @quadrille38 . After reading the Jabsco 37045 manual, I see it's the same as a domestic toilet except it uses a discharge pump rather than gravity to empty the bowl contents . Potable water supply and bowl contents are completely separated at all times.

 

[quadrille38]

If it's specifically designed for use with a pressurized water system, great! And you also have the owners manual for it...I'm impressed!

--Peggie

oh yeah that’s an idiosyncrasy of mine - not only do I have the manuals I like to sit and read them LOL
I will admit to being a nerd. Every fall when I pull the boat for the winter I bring the huge pouch of manuals home and throughout the winter I pull them out and re read them. Amazing what features i still discover even after 11 years LOL.

 

[Peggie Hall HeadMistress]

And I thought I was OCD.....

--Peggie

 

[Ken Cross]

Also the seacock connected to the macerator or Y valve if you have one is required to be locked in the closed position or the handle removed. As I understand it, that's a legal requirement in the US. Someone correct me if I'm wrong, please.

Ken

 

[jssailem]

Ken. I passed the annual CG inspection with having the thru hull valve zip tied closed and the wires to the pump disconnected.

 

[pumpkinpie]

Thanks for everyone’s replies. Throughout this “quarantine” we have been on our boat quite a lot and had plenty of time to learn more about different things, including how a pump out using the thru hull works with our system.

I believe we do have a system identical to @quadrille38 as we have the same model boat and everything he’s described sounds the same.

Our head pulls fresh water and once flushed, it goes through the grinding macerator pump and directly to the holding tank. There is no other route possible between these two points. Next, we have the option to pump out at the dock, or using the thru hull out at sea. To pump out using the thru hull, the valve downhill just before the macerator pump must be opened, along with the thru hull itself.

We recently took our boat out offshore to attempt a pump out to make sure all works well. Unfortunately it didn’t work out as well as we would have hoped.....

We opened the valve and then the thru hull, pumped her out, closed the valve first, then the thru hull. It was at that point we noticed a small leak start to spread from under the macerator pump. We dried and cleaned the area, placing paper towels to catch any further drip. We checked it the next day and see that it still has a tiny leak. This area is quite tight to get into. Worse than when we had to change the macerator pump (both are Jabsco pumps) next to our head which also ended up getting a small crack in the plastic and ended up leaking too. I’m not sure if that’s what has happened here, or if we shut the valves in the wrong order, leaving discharge in the lines that may have caused pressure to leak out somehow, and/or both. Is there a specific order in which the valve and thru hull should be opened/closed? Any thoughts?