Macerator/Waste holding tank

[Fowl Hooked]

I did the y-valve and external macerator on my 265 based on Max366's original thread. It's not the most convenient thing in the world if you need to switch back and forth as you've got to open the access hatch under the starboard seat after moving everything out of the way but like most others I'm perpetually in pump-out condition so the repair was really just 'to have everything functional'. Handle for the overboard discharge seacock is removed and kept in a zip-loc along with the fuse for the macerator. Hopefully it'll never have to be done again.

 

[Hookup1]

I have been having a problem getting the pump to prime after sitting for a long while. Put some water in the hose and it will pump out fine. Modified the install with a 90 degree reducer 1" to 3/4" and installed a 3/4" vented loop. It more about keeping some liquid in the hose at the pump. To winterize I'll have to pull the 90 degree hose, dump out and use vegetable oil - not sure if the impeller will tolerate the alcohol in the pink antifreeze.

 

[DennisG01]

I have been having a problem getting the pump to prime after sitting for a long while. Put some water in the hose and it will pump out fine. Modified the install with a 90 degree reducer 1" to 3/4" and installed a 3/4" vented loop. It more about keeping some liquid in the hose at the pump. To winterize I'll have to pull the 90 degree hose, dump out and use vegetable oil - not sure if the impeller will tolerate the alcohol in the pink antifreeze.

It sounds like you need a new impeller?

Instead of the pink stuff with ethyl alcohol, you could use the pink stuff with propylene glycol.

 

[Hookup1]

I'll probably change the impeller too. It was replaced but last time I tried to pump out it took a beating.

 

[ttles714]

I got tired of going into the tank and freeing up the pump .... a really stupid design ..... if i recall there was a threaded fitting on the top side of the tank ... i installed a pvc piece of pipe into that port and connected a Jabsco maserator pump using the existing discharge hose on one end and a connection to the pvc pipe on the other ... I also recall installing a Wema guage and sending unit to the existing gauge wiring and installing the gauge where the old electronic one was in the cabin . ... a much simpler and more dependable system !!

 

[DennisG01]

I'll probably change the impeller too. It was replaced but last time I tried to pump out it took a beating.

Did the housing/etc all look good? It doesn't take much of a scratch/gouge at all to affect performance. Often, all it takes is a scratch where you can just barely "catch" your finger nail.

 

[Hookup1]

Not my favorite project. I'm going to put it together and see how it works. I know the pump works. I pumped out into a bucket last week. Holding tank seems to be about 4-gallon. If I have to pump it out before going out I'll disconnect hose, pump into bucket and dump in the toilet in the house.

In the Keys they really don't want you to pump out overboard at all! Yet there are not a lot of places that do pump outs. The town's actually have a schedule to stop by your boat and pump it out. The only marina I found was Bass Pro Shops in Islamorada. No discharge within 3 miles on the ocean side and 9 miles on the Gulf side.

https://reefrelief.org/pdf/NoDischargeBrch.pdf

 

[ROBERTH]

I did the retrofit macerator replacing the in-tank Groco a few years ago. Starting having issues last year where it would not pump out when way out to sea, but when I got home and on the trailer, it would pump out when I tested it. Assumed air leak, so resealed fittings and put new hoses with double clamps. All good, then same issue again this year. I turned the 3 way valve a few weeks ago and it started pumping so figured it was leaking as was original 3 way valve. Last week I installed direct hose to pump and it would not pump out, so now have to figure replace the pump. You can hear it spinning, just nothing pulling. So will try to install a new pump this weekend and see if that is the fix. Maybe is it just getting weak or as mentioned, has some scratch or impeller worn out. I don't use it much, so hard to believe the impellor would be worn out.

 

[Hookup1]

Someties its the vented loop. And sometimes it's that it won't automatically prime. I've been dealing with this for 20+ years on various boats! Maybe I finally earned my PhD in MSD!

 

[Legend]

GW and Groco got back to me with diagrams of the holding tank monitor panel and the in-tank level sensor. Panel is discontinued but in-tank sensor is available at a price. Mine isn't reading correctly and wanted to have a look before closing things up. Thought someone might need this information at some point. Groco GM-50 Groco GM-450
View attachment 17514

My in tank monitor never worked the way a monitor should. I replaced mine with and external tank monitor about a month ago and it works great and is extremely accurate. It does not have and on off switch for the macerator like the original so I just used an unused accessory switch on my cockpit panel and finished it off with a macerator switch cover.
The tank monitor a TM1 made by Scad Tech - cost is 169 at many on line boat suppliers or EBAY - very simple to install

 

[Hookup1]

I tried to get the level detector out of mine last year. It an odd 2" 8-sided head that screws in. I think they contact cemented it in because it wouldn't budge. So I just cleaned the contacts up. The Groco display will show empty (< 25%), 50% not working and 75%. It's a small tank and really has to be emptied frequently. I'll just live with it. But thank you f.or the your suggestion. Good info.

Getting the pump to reliably work is more important to me. I think I have that fixed with a vented loop that should water and peep the pump primed. One hose came to move and I'm done for now.

 

[ROBERTH]

Update to my comments above. I replaced the Macerator pump this weekend and also installed a new Sea-lect 3 Way valve and all is pumping again.
Pretty sure the 3 way valve was not the issue, but it is about 30 years old so the rubber seal is hardened and might be a problem at times.
The old pump I removed and took apart shows that likely the impellor is the culprit as it has hardened and did not have any flexibility, so therefore is not getting a good seal to have good suction power. The motor is fine so will order a new impellor and have this pump as a quick swap backup next time the impellor goes bad in a few years.

 

[Brian F]

In 25 years of running between MA and FL, I have been boarded for USCG inspections 4 times. Each time the CG crew boarded us they have been professional and polite. But, not once did any of them inquire about or inspect the overboard discharge valve. Long ago, I did have it wired closed but actually have forgot about it being open until I saw this thread.