Winterizing Macerator

[Warren]

Once the toilets were winterized I poured 6+ gallons of antifreeze into the holding tank through the pump-out fitting on deck. After opening the through-hull fitting for the macerator, I turned on the macerator pump expecting to find antifreeze (well, mostly antifreeze) on the ground under the outlet.

Nothing! The pump sounded OK and the boat is in it's cradle, bow up. There is no 'Y' valve - just a short hose from the aft base of the holding tank leading to the macerator pump, then a loop up above the tank descending to the opened through hull fitting.

Anyone know what's happening here? Do I have a pump problem?
Advice appreciated,
Warren

 

[estebanj]

How big a tank? 6 gallons may not be enough to reach the pick up for the macerator tube.

Esteban

 

[Warren]

Good question. I believe the tank is 35 gal. there should be lots of antifreeze there for the job - in fact I would think that only 1-2 gal would be sufficient as, as I said earlier, the drain to the macerator is right at the bottom of the aft end of the tank.

I was wondering if it wouldn't pump as there is no back pressure on the outlet tube as the boat is on the hard. The outlet would normally be under water. I was thinking of fully or partially closing the through hull to simulate this resistance and then opening it while the pump was still operating. I might try that when I'm at the boat, unless you have another suggestion??
Thanks,
Warren

 

[fwebster]

Just stop where you are and remove the mascerator from the boat. If the diaphram and duck bill valves in it are good, it should have primed itself and removed the antifreeze from the holding tank.

The pumps are very simple and repair parts are available from any SeaLand dealer. Here is a dealer locator:

http://www.sealandtechnology.com/pdf/webMSDlist.pdf

and, here is a parts breakdown:

http://www.sealandtechnology.com/pdf/600340678 Discharge pump instr.pdf

The pump will not freeze in your shop or basement and you have all winter to rebuild it, but I'll tell you to look for debris caught in the diaphram or stuck in one of the duck bill valves. If you have been using a shore side pump out and have left the thru hull valve past the mascerator in the bottom of the hull open, the chances are good that you have a missing duckbill valve on the inlet end of the pump where the shore side pump out has sucked it out. To avoid this in the future and facilitate easy and clean removal of the mascerator if you need to service it again, get some hose barbs and a pvc ball valve and put the valve just ahead of the mascerator and keep the valve closed when you are not using the mascerator.

Some of us have been thru this a number of times and we'd be more than happy to help you fix it.........it just too bad that you are so far away (whew)!

 

[Warren]

Yes, I think you have identified the problem Frank, the last pump-out was done with the through hull open while I sucked and pumped, sucked and pumped, etc. Also thanks for the links. It sounds like the pump needs work and, yes it is very unfortunate that you are so far away - I know how much you will miss crawling into that tiny cavity on your belly and spending 30 minutes sniffing my waste and dodging my effluent.

More seriously, assuming that I do find the resolve to do this job - some other practical questions: There are SIX gallons of windshield washer antifreeze in that holding tank. Would you let it all drain into the ER and find it's way out of the hull drain plug (along with the inevitable residues)? It will be difficult to rinse the ER out without a hose - buckets of water I guess. Or would you try to get a tapered plug or equivalent into the tank outlet port before removing the pump? Or would you wait until spring, pump out and fix the pump, install the ball valve etc. then?

So... I have learned a lesson with your coaching. Never use the shore side pump out with the macerator through-hull valve open! A valuable lesson. Many thanks Frank!
Sincerely,
Warren

 

[fwebster]

Warren,

Shop-vacs are wonderful inventions.

When I did this on my boat......I didn't have antifreeze in the holding tank; just a bad duck bill, and the need to be sure I didn't have an enviornmental disaster in my bilge.....I was able to use a towel and a shop vac and completely avoided any spillage.

Try to remove the 4 screws holding the macerator pump to the deck, clip the power wires (at the butt splice but leave enough wire so can see its color....cut the existing butt splice completely out and replace it with a shrink type when you put the maceraror back in). Now the pump is loose except for the outlet and inlet hoses....remove the outlet hose with a towel under the connection and with the shop-vac running at the connection to the pump to catch anything that spills. Now the pump is free. Get some help from above and hold the macerator pump as high as you can get it......take cable ties or clamps loose if you have to.....but the goal is to get it higher than the outlet on the holding tank. Do the towel/shop-vac thing again. Have your new 1-1/2" ball valve ready, then quickly remove the inlet hose, cut off a section as long as the ball valve, then put the valve on the hose, tighten the hose clamps and close the valve.

Now, you have a quick-change macerator for next time!

Be careful, don't hurry and I bet you can do this in a few minutes with no spills too.

 

[Warren]

Very good advice and I will try to follow you procedure as closely as I can when I am able. However on the 400SD there is only about 6" of hose between the tank and the pump proper - not enough room to gain the elevation required for the manouvre you describe. So I will have to rethink this plan. Worse case scenerio to somehow pump the holding tank til it's almost dry. .

That would work if I can find a method to empty it. Otherwise - would you agree - spring project???
Warren

 

[fwebster]

Here are 2 more suggestions:

1. If the macerator has bad duck bill valves and won't pump as we suspect , you can probably hold the shop vac up to the outlet on the bottom of the hull and suck the tank dry.

2. You can remove the tank sending unit and stick the shop vac hose down in the hole to access the waste/antifreeze to pump it dry.

I don't know how you guys up north do it. Having something like this wrong with my boat would eat me alive until I fixed it......I could not possibly wait till spring. I wish I were a little less type A..........