Troubleshooting Macerator Pumpout Problem

G

GrecRI

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Generally, we take our last cruise of the season after all pumpout stations in the area are closed. So, we've made a tradition of going offshore one last time - usually to Block I - and pumping out whatever might be left in the holding tank during the trip.

This year, to my surprise, the macerator was 'anemic' to the point of being incapable of pumping out the 1.5 or so gallons that were left in the tank.

The pump sounds fine when it starts, but then quickly winds down - to a complete stop within about 10-15 seconds.

If I wait a min and try again it repeats the same scenario.

After hauling for the season, I removed the waste tank (which is built into the bottom of the toilet and connected to both the macerator and pump out connection) and tried the pump again with the waste hose open at the toilet end.

Same result. Runs fast, slow, slower, stop. I hear gurgling in the waste hose when the pump is on, so I don't think I have any blockage.

Sometimes, when the pumps slows down a squeak emits from the pump head. This pump is only 2 seasons old and has probably only been used 6 or 7 times. It has a run-dry feature, but when this occured, there was enough liquid in the holding tank so it shouldn't have run dry.

It's a real project to pull the hose connections apart because the hose fits so damn tight to the fittings. I'd like to trouble shoot the problem without disconnecting any more fittings than I have to. I actually found it easter to cut the hose from the waste tank than to disconnect it from the fitting. Will heating the hose help loosen it?

Anyway, just curious if there is something else I should try before pulling the pump, which is a real project due to it's inconvenient location and the tight hose connections.
 
Check the voltage going to the pump as it is running. And for the heck of it rap on it with a mallet or a hammer while it's trying to run. But if it's your typical Jabsco or Jabsco like pump it wouldn't surprise me if it's toast. If it is and you have to replace it look at putting in a Sealand diaphragm pump.
 
Sounds to me like you have a blockage between the tank and the pump making it run dry and overheat. As it heats up it will slowly seize. Even a so called "run dry" macerator will do it.

I had the exact same problem earlier this year. In the end, when you find the cause go ahead and replace the pump.

Bob
 
My initial thought was blockage too, but I don't think I'd hear gurgling in the hose if there was blockage, would I?

Pretty frustrating if I have to change it out again so soon. I changed it during the summer of 2010. But yes, it's a Jabsco.
 
quote:
Originally posted by GrecRI

My initial thought was blockage too, but I don't think I'd hear gurgling in the hose if there was blockage, would I?

Pretty frustrating if I have to change it out again so soon. I changed it during the summer of 2010. But yes, it's a Jabsco.

Click to expand...


Well, since you've already taken everything apart, stick the intake of the pump in a bucket of water (off the boat) and power it up. If it shoots a stream of water from the outlet side, the pump is fine, the problem is somewhere else.

You can buy a rebuild kit for those pumps
 
Ralph, the macerator pump may have a burnt-out rubber impeller inside it. It needs to pump water, which acts as a lubricant. when it isn't pumping water, there is additional drag on the impeller, and on the motor. Follow the suggestion about pumping out of a bucket if it can be done without too much difficulty. Otherwise, try replacing the impeller.
 
I've kind of gone full circle on this.

I checked into diaphragm pumps, but the pump compartment is quite small, making the installation of most of the diaphragm pumps I found a difficult or impossible endeavor. I found one Jabsco diaphragm pump that might fit, because it offered the ability to rotate the head on both planes. But all the diaphragm pumps I found, including that one, have a 1.5" outlet. My discharge line from the existing macerator is 1". I really don't want to enlarge the hole for the discharge fitting in the hull, and given that the diaphragm pumps don't do anything to reduce the size of the debris passing through them, I assume this would present a potential clogging problem. Am I right about that?

Additionally, I don't think I could conform a 1.5" hose to make the bend I need to make between the pump and the discharge fitting.

If a diaphragm pump isn't an option, I may reluctantly install another macerator pump. At least it would fit right in where the last one came out. The biggest concern I have about re-installing it the origional way, is that I assume I'll be doing this again and there is no easy way to remove it. It's impossible to remove 1.5" hose from the fittings in those tight quarters, so you have to cut the hoses and replace them every time you have a problem.

I started looking for some kind of quick disconnect fitting for 1.5" hose, that would make it easy to remove and replace the pump in the future, but I haven't found anything that I consider appropriate. I found some quick couplers, but they had steel rings on them. Is there any kind of quick disconnect union or coupling made for this purpose in a marine environment?
 
Diaphragm pumps do smash the stuff up. As do most if not all heads. So going from 1.5 to 1 inch line shouldn't be an issue.

As to quick disconnects, go to a hardware store or HD and take a look at using these:

PVCdisconnect2.jpg


They come a part by unscrewing them.
 
Ok, so I tried the pump again dry before trying it in the bucket. The same thing happened out of the boat as what happened in the boat. It started fast and slowed down to a stop within about 10 seconds.

Then I used the 'bucket method' above. It pumped fine and kept pumping. So, I decided to try it out of the bucket again to see if anything changed after it was exposed to the water. Now it runs fine - even out of the bucket. It was running dry for 15 seconds or so with no problem. It has an automatic shutoff if it runs dry for too long but I didn't wait for that to happen. So, it appears that the impellor was dried out - probably from lack of use.

I'm thinking that if I stay with this pump, an idea which I'm not very enthused about at this point, I should at least get the rebuild kit based on the assumption that this impellor will stick again when it drys out.

I hate the idea of throwing $300 at a diaphragm pump and figuring out how to retrofit the installation, but I'm really not into doing this every couple if years either.

Capt. Bill, is PVC okay in a waste sanitation line? I thought you had to use polypro to prevent odor seepage. I found threaded unions like that in polypro, but they were extremely expensive.
 
The discharge can be reduced. I've done it, with no issues.

I should point out I'm speaking about the Sealand pump. In fact they come with a reducer.
 
Capt. Bill 1,
I will respectfully disagree. No where in the Sealand Super Tech Training Program and
Installation guide does it say its ok to reduce the discharge line size. In fact, I've replaced many ITT Jabsco with the Sealand, and always changed out the thru hulls to 1 1/2.
Diaphram pumps do not macerate or reduce the size of the waste, like the ITT Jabsco does. It has a cutter inside that reduces waste and paper to a small size. It may work, but not recomended.
 
"SEALAND MACERATOR AND VACUFLUSH PUMPS

Sealand originally developed the rugged “T” series line of bellows sewage discharge pumps
for their own toilet systems. However, it was so successful they have made it available for
all sewage discharge applications. These pumps will move up to 200 gph, handle 1/2"diameter
solids, and accept 1 1/2" slip-on hose (1 1/2" x 1" hose adaptor is included)."

Note the last set of bracketed words. :-)

Normal poop is made up of mostly water. Heads break it up pretty well. Then when it passes through a diaphragm pump it breaks up even further.

Changing the lines and thru hull to 1 1/2" would be ideal of course but 1" will work.
 
I just tried again and signed in as a new user instead. It appeared to go through okay that way.
 
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