Failed macerator pumps

[JebLostInSpace]

So neither of the macerator pumps for my two holding tanks are working. They are both Jabsco pumps. They make noise and draw a ton of amps (way more than they should, so maybe a short?), but don't empty my tanks. I have a few questions, as I've never worked on these types of pumps before.

Is there any likelihood that these can be repaired? Most times a pump isn't working, I assume an impeller failure first. Can you replace an impeller in these pumps? Is it worth it to try? I assume it will be a horrific nasty job if I do it. Maybe it makes more sense to replace rather than open the pump up, or maybe I'm just being a wimp. One of the pumps lives inside the headboard on the main bunk, so I'm quite unwilling to release a lot of holding tank contents in that location

What would it take to eliminate the macerator pumps entirely? When I've chartered boats, they usually have a simple y-valve configuration that just lets gravity empty the holding tanks when at sea. This is actually the only boat I've been on that has macerator pumps to suction the contents out of the tank.

My understanding (subject to correction) is that the use of macerators makes me a Type I MSD if I also treat waste with disinfectant before releasing it. Since I don't use disinfectant, I'm still a Type III. Is there any other advantage to having the macerator other than trying to qualify as Type I? I don't really have any need to qualify as Type I MSD, since I only dump when offshore anyway.

[Simi 60]

Impeller kit
Easy fix
Sh1te washes off.

We bought one of these $80 cheapies as a spare
https://www.ebay.com.au/itm/25425413...oAAOSwzcJc92kL

It's been in and running for well over a year while the rebuilt Johnson sits in a box for next time.

[zboss]

Electric macerator pumps are generally junk. I have one that is not even 3 months old and is leaking.

On our last boat I replaced the electric macerator with a manual Mk 5 Sanitation Pump and never had any problems after that.

[chrisr]

Originally Posted by zboss

Electric macerator pumps are generally junk..

hmmm...that's a sweeping statement !

while it might be your experience, we have two electric macerator pumps which have been going strong for well over 10 years - and we are full time live aboards so they get used a lot. chew up anything short of a 10" shifter, never clog and never fail !

perhaps there is some variety in installation or brand quality ?

in answer to the OP, our holding tank has a simple dump (pardon the pun) valve...no pump to empty. works fine, but we macerate on the way in, not out.

cheers,

[Windpilot]

Use a pump out first to empty the holding tank.
Make sure sludge isn't blocking the maceraters intake.

[belizesailor]

Yes, they are generally easily repairable. The syptoms sound like typical junk on the impeller/chopper blade. These tend to get gunked up and then dont work effectively. Likely only need cleaning. Install new gasket(s) at the same time.

Man up: put on some gloves and clean the pump head.

Diaphram pump or gravity dump, depending on which is feasible on your boat, are less trouble prone solutions.

[zboss]

He is specifically asking about emptying the holding tank.

[Shanachie]

Check for a clog. Not a pleasant thing to do, but necessary.


Close the through hull and remove the hose clamp and hose. Then open the through hull briefly. If you get lots of water, I'm wrong. If you don't, use a screwdriver to clear the through hull and clean up the mess.


Two pumps at once tell me that you have some growth or organisms clogging your through hulls.

[Windpilot]

Originally Posted by zboss

He is specifically asking about emptying the holding tank.

Factory holding tanks have deck pump outs, never have I seen one without one. Use a Dockside pump out, then work on the macerater.
Macerater is only good for pumping out at sea.

[Sohum]

Replaced 2 Jabsco maceraters, they were tired, I’m glad I did.. I rebuilt one, the plastic housing and plate worn. I should’ve just replaced due to age. The o ring seal on my model is awful, slightly too big imo.. I used permatex around the o ring to help seat and hold.
These new ones are great. I treat with marine digest it.

[Simi 60]

Originally Posted by Windpilot

Factory holding tanks have deck pump outs, never have I seen one without one. Use a Dockside pump out, then work on the macerater.
Macerater is only good for pumping out at sea.

Our pump out fitting is in the ER, not that we use it as there are no dockside pump outs here that I know of.

Both toilets have macerator pumps
Into a treatment plant
Into a holding tank
And macerator pump out the side when full.

[LLCoolDave]

I have a jabsco electric head. The macerator pump is at the head base. You then select the y valve to direct discharge to overboard or to the black water tank. The only way out of the black water tank is a pump out.

[NYSail]

I removed both of mine and switched my tanks to gravity discharge. One best decisions I’ve made. Removed at least 6 feet of extra hose and a y valve that smelled. Deck pump out and gravity for when at sea!
Greg

[JebLostInSpace]

Thanks for all the replies and advice so far. To clarify, I'll post a quick overview of the current system setup. I didn't realize how much variety there was in how these are set up, so apologies for not including this information earlier.

I have 2 heads, both with the same system, but the two systems are completely independent from each other. I have a manual-pump head which draws sea water into the toilet bowl, and then pumps the bowl contents through a short length of hose to the holding tank. There are 2 options for removing the contents from the holding tank. I have deck fittings that allow a pump-out when available. The other option is to discharge overboard, which I only do when at sea. There is a length of hose running from the holding tank to a standalone macerator pump. Then another length of hose from the macerator pump to the through-hull. To empty the tank, I run the macerator pump, which draws waste from the tank, chops it up, and pushes it through the through-hull.

Now a couple of follow-up questions based on what you all have said so far:

zboss: A manual pump is definitely appealing, as less prone to failure. Does it need a lot of clearance for the pump handle? My current macerator pumps are tucked away in pretty tight spots, so I'd have to think carefully about clearance. Also, does that pump macerate as well, or just shove the waste out? And is there any reason I should want it to macerate?

belizesailor: If I take it apart to clean, what all should I be prepared to replace while it's opened up? I assume impeller and gaskets. Should I be prepared to replace the blades? Are there o-rings I need to know about? I'll look up a parts list for my specific model, but any tips about trouble areas would be helpful.

shanachie: I don't think it's likely that I have a clog at the through-hull for a few reasons. I have a diver scrape my bottom every couple of months, so there shouldn't be a ton of growth, and any waste exiting at the through-hull should be macerated, which I assume makes it less prone to clogging.

NYSail: When you removed yours, did you have to make any changes to the holding tank or through-hulls? My through-hull is right next to the tank, with the tank sitting on the same part of the hull as the through-hull. This means the through-hull is even with the bottom of the tank. Would I need to raise the tank a little bit to encourage draining? Since the holding tank is below the waterline, I'm not really clear on whether it would drain at all, or if it would fill with sea water when I open the valve?

[Windpilot]

I have to same set up as you except freshwater flush.
As my pumps are over $200., to be practical I would install 1 new one and try to repair, if possible, the one removed. If you can get it to work again use it on the other tank and do the same with that pump. It's always good to have a spare around with 2 holding tanks.
You may find them easy to repair or too corroded to repair, you won't know till you take it apart.
But make sure the tanks discharge port is clear, I've replaced a pump before when it was just a paper/sludge clog.