macerator not emptying holding tank

[jclays]

Good afternoon
Mainship 350 1997 two weeks new to me. Filled the empty holding tank with water and a little bleach to sanitize. After a week back to the boat to empty. Seacock open flipped the macerator switch. Macerator running but not pumping out. Not priming???

 

[rgano]

I recently finished changing the macerator pump on my tak for the second time in a couple of years. The most recent failure was of a VERY little used pump. I attribute this last failure to the fact that the boat sat in the water instead of in its lift while the lift was repaired from hurricane damage with the seacock POSSIBLY left open allowing slight seawater pressure into the pump which itself sits a little above the 2/3 full level of the tank. An autopsy of the pump showed corrosion into the motor bearing from the pump section. If your tank was full of a chlorine solution with the pump down low, you may have killed the pump.

 

[NorWyn]

Just replaced ours in the (relative) middle of nowhere. It sounded like it was working but no pump out.

Had a rebuild kit on board...never again.

Was fortunately able to source a new one on our route and install it with excellent result.

For the $200 for a brand new self priming pump I would never attempt the rebuild thing again.

Not sure about putting bleach through the system but others will know more than me.

Good luck

 

[High Wire]

Impeller shot or air leak on the suction side. Also check for a valve or tee on the suction side to the deck pump out fitting. Every boat is plumbed differently.

 

[menzies]

Good afternoon
Mainship 350 1997 two weeks new to me. Filled the empty holding tank with water and a little bleach to sanitize. After a week back to the boat to empty. Seacock open flipped the macerator switch. Macerator running but not pumping out. Not priming???

Did you open the deck cap? If not try that in case the vent is clogged. Air needs to get in to replace the water.

 

[boomerang]

I'm not sure how your system is plumbed but is your y-valve open from the tank to the deck fitting and not the pump? I would check that.

 

[Comodave]

You don’t need to sanitize the holding tank. Besides the first time you put poop into the tank it won’t be sterile anymore. Just flush it with clean water. Besides bleach will kill the bacteria and you do want aerobic bacteria growing in the tank. Anerobic bacteria are the bad kind, they cause smells, and they come from lack of oxygen. The solution to get aerobic bacteria is to get lots of air into the tank. If you have a filter on the vent that will contribute to anerobic bacteria growing and smelling.

 

[Bacchus]

Agree with comments above - could be pump or vent or combo.
Have you pumped out via deck fitting to ensure vent is working OK?
Vents are notorious problems and most Mfg use the wrong (fule vent) fittings and the small openings & screens plug often. Lots of threads about holding tank vents, size, fittings, routing, etc.
My macerator sat below the tank discharge so no priming issues but was corroded and leaking when I got my boat. I'm inland on fresh water lake sao just eliminated it instead of replacing.
As others said bleach doesn't help holding tanks as you are not trying to sterilize.; What you really want is aerobic bacteria action which requires getting air to the tank via adequate venting. Most (including myself) report good results using NoFlex Digester or Sodium Percarbonate (active ingredient in NoFlex) to help promote aerobic action and keep the tank "clean"
Worst case some (myself included) have resorted to installing bubbler to aerate the tank. My website linked on my signature includes details in the "Projects" section. I have since rerouted and increased the size of my vent but the bubbler is still running 24/7 during the season so I figure I'll continue to let it do its thing.

 

[menzies]

BTW, this is probably a god place to pontificate on one of my mantras.

Start with the most simplest (and in most case cheaper) resolution first and work your way towards the more complicated (and usually more expensive ) solutions.

This is a lesson borne of implementing fixes which cost more, only to find a 50c solution fixed the problem!

Good luck!

 

[Fletcher500]

My mascerator pump died today. Breaker would open after a few seconds so I did the screw driver on the pump motor to manually turn the impeller figuring it would be an easy fix. Nope, and I am a ways away from sourcing a new pump. Time for the bucket for awhile until I can get to a pump out station.

 

[menzies]

My mascerator pump died today. Breaker would open after a few seconds so I did the screw driver on the pump motor to manually turn the impeller figuring it would be an easy fix. Nope, and I am a ways away from sourcing a new pump. Time for the bucket for awhile until I can get to a pump out station.

Holding tank full?

Hang it over the side, no one will know!

 

[Fletcher500]

Holding tank full?

Hang it over the side, no one will know!

I just gave my son the third lecture of the day not to pee in the toilet and he is not happy with me.

 

[jclays]

when i bought the boat the holding tank had waste in it. It did not empty then. The delivery captain had it pumped out and cleaned. The cabin of the boat had some odor so i put water and bleach in the holding tank to hopefully eliminate some of the odor. there is a PVC Tee at the bottom of the holding tank. One hose goes to the deck fitting the other side of the Tee goes to the macerator pump. No Y valve. The hose from the out put hose from the macerator to the seacock is wet and is leaking discovered after looking around a few days ago. Before my purchase the boat sat unused for about 6 months.

 

[menzies]

when i bought the boat the holding tank had waste in it. It did not empty then. The delivery captain had it pumped out and cleaned. The cabin of the boat had some odor so i put water and bleach in the holding tank to hopefully eliminate some of the odor. there is a PVC Tee at the bottom of the holding tank. One hose goes to the deck fitting the other side of the Tee goes to the macerator pump. No Y valve. The hose from the out put hose from the macerator to the seacock is wet and is leaking discovered after looking around a few days ago. Before my purchase the boat sat unused for about 6 months.

That PVC T is a Y valve! (not a lot of difference in the letter!).

Make sure the leak is between the macerator and the through hull, if it is on the holding tank side of the pump it may be causing your problem.

 

[menzies]

I just gave my son the third lecture of the day not to pee in the toilet and he is not happy with me.

I wasn't just talking about pee!

 

[jclays]

That PVC T is a Y valve! (not a lot of difference in the letter!).

Make sure the leak is between the macerator and the through hull, if it is on the holding tank side of the pump it may be causing your problem.

It’s actually just a white PVC T. It is not a valve in anyway. You cannot isolate the macerator or the deck pump out like a true y valve.

 

[Woodland Hills]

Why screw around with a macerator pump when a diaphragm pump will self-prime, run dry with no harm and will pump solids? I replaced our macerator pump with a Sealand diaphragm pump and haven’t had any issues since.

 

[tiltrider1]

There is one other possible answer here. It is possible that the through hull is clogged. Would be same effect as not opening the valve.

 

[jclays]

Will check when I replace the macerator to seacock hose

 

[Northern Spy]

First step in troubleshooting a macerator is turning the motor shaft CCW with a screwdriver. Oftentimes this frees it up.

Turn it on again.

If it runs and cuts out again, it is likely not the motor. Open it up and remove the dental floss, chunk of gravel, or whatnot. You may have to replace the impeller/blade. It is a pretty easy task. If you buy the kit, you get an O-Ring. If it is just plugged, be careful with the O-ring, get a new one from a auto shop, or replace it with one from your O-ring kit. As long as you aren't using all sorts of chemicals in your tank, Nitrile, would be fine.

If it doesn't run, then it is a motor issue. Best to replace the whole macerator.

I'm no Jabsco fan, but I'd bet many macerators are tossed because they are plugged with something and it damages the impeller, and the owner or tech, just doesn't want to deal with it.

Running them dry accelerates wear and tear and loose the ability to self prime. Probably what happened here. Price out a kit versus a new macerator and see if it is worth dinking around with.

You always buy a new one and bench repair the old one, if possible at your leisure (maybe not the best word choice).

 

[ktdtx]

I replaced our macerator pump with a Sealand diaphragm pump and haven’t had any issues since.

YES!


I had a similar, recurring problem which required aggressive back flushing from the thru hull--redid the system with PVC and more appropriate sized and type hose. Also replaced Jabsco macerator with Sealand and then NO MORE problem.


I might have an idea that the seller knew there was a problem.


Ken

 

[Swfla]

Did you open the deck cap? If not try that in case the vent is clogged. Air needs to get in to replace the water.

There was a recent thread about a tank split because the vent was clogged and the vacuum of the pump crushed the tank.

 

[Alaskan Sea-Duction]

That PVC T is a Y valve! (not a lot of difference in the letter!).

Make sure the leak is between the macerator and the through hull, if it is on the holding tank side of the pump it may be causing your problem.

when i bought the boat the holding tank had waste in it. It did not empty then. The delivery captain had it pumped out and cleaned. The cabin of the boat had some odor so i put water and bleach in the holding tank to hopefully eliminate some of the odor. there is a PVC Tee at the bottom of the holding tank. One hose goes to the deck fitting the other side of the Tee goes to the macerator pump. No Y valve. The hose from the out put hose from the macerator to the seacock is wet and is leaking discovered after looking around a few days ago. Before my purchase the boat sat unused for about 6 months.

Your macerator pump is sucking air. Either the impeller is shot or as I found mine a few days ago the pump bolts/screws that hold the impeller onto the pump. Replace the pump. They are about $200 at WM.

It’s actually just a white PVC T. It is not a valve in anyway. You cannot isolate the macerator or the deck pump out like a true y valve.

I am surprised the surveyor let that go., but if you look at it it works for pumping waste from the tank. Not sure if pumping from the deck can damage the macerator.

My black tank has one inlet and two outlets. One for pumpout through the deckfill and one for the macerator.

 

[timb]

I am surprised the surveyor let that go., but if you look at it it works for pumping waste from the tank. Not sure if pumping from the deck can damage the macerator.

mine is the same way but it has the cap on the deck fitting and the seacock on the pump should work fine . but mine doesn't work so i can't say .i i don't plan on using mine much but the hoses to the deck and pump are the only one left to change so i want to change the pump at the same time. i am dreading taking the lowest hoses on the tank off.

 

[Fletcher500]

My Jabsco Masc Pump is going in to the trash when I get back and will be replaced with a Sealand based on the comments here.

Edit: KTDX: how did you back flush through the thru hull?

 

[AusCan]

For emptying a holding tank, a macerator pump is the 3rd best option. They are expensive and unreliable. A diaphram pump is better.
I find the best solution is gravity. Mount your black water tank above the water line and just open the drain valve to empty.

 

[High Wire]

The deck fitting has an O-ring that if cracked will cause your problems. Very easy to check!

 

[bligh]

when i bought the boat the holding tank had waste in it. It did not empty then. The delivery captain had it pumped out and cleaned. The cabin of the boat had some odor so i put water and bleach in the holding tank to hopefully eliminate some of the odor. there is a PVC Tee at the bottom of the holding tank. One hose goes to the deck fitting the other side of the Tee goes to the macerator pump. No Y valve. The hose from the out put hose from the macerator to the seacock is wet and is leaking discovered after looking around a few days ago. Before my purchase the boat sat unused for about 6 months.

Ok since the pump out fitting/line is connected to the macerator line, make sure the deck fitting of the pump out has a good o-ring and is sealed tight. Otherwise the pump will not prime with effluent.

 

[mahal]

mine is the same way but it has the cap on the deck fitting and the seacock on the pump should work fine . but mine doesn't work so i can't say .i i don't plan on using mine much but the hoses to the deck and pump are the only one left to change so i want to change the pump at the same time. i am dreading taking the lowest hoses on the tank off.

In case you weren't aware, you can apply vacuum to the tank to keep remnant black water from from coming out when replacing the hose. Attach a shop vac to a fitting on the tank's top, like the fitting for the hose from the head. Plug the vent line and any others that might allow air in. Turn on the shop vac and swap hoses.

BTW, discharge hoses that attach to the bottom of the tank (instead of the top with a dip tube) are subject to premature permeation since it's always full of crap. A workaround solution is to install a rigid sched.40 PVC pipe installed vertically or close to it up to the tank's top (external dip tube?) before the flex sanitation hose. Better yet, use PVC for as much as you can if you have straight runs.

If you're upgrading to a diaphragm pump, with your plumbing set-up, which is similar to mine, make sure that your discharge valve is always closed when at the pump out. Or the duckbills in the new pump might invert rendering it inop until corrected. Don't ask me how I know.

 

[mvweebles]

Last year when I was getting ready to leave San Francisco for Ensenada (a 75-hour non-stop run with myself and two crew ---- and one head), my macerator died (more accurately, it died a while back, just decided now was the time to replace). I got a new Jabsco from Defender. I installed - it would run and make a gurggling sound like it was emptying the holding tank, but then not actually move anything. I figured it must be an install error or something related to the boat sitting for a few years. I spent 1-1/2 days checking current, breakers, everything I could think of. Man, what a mess - I re-installed the dang thing a couple times.

Finally I bought a brand new one at West Marine's shylock prices. Worked like a champ! The original Jabsco was DOA. I sure wish I'd figured that out several-manhours earlier. It really bummed me out - I was trying to figure out what to do with three persons onboard for 3-days. Not like I could go headless.....

Hope your experience is better than mine. Made me think long and hard about a composting head.......

Peter