Marlin head/waste tank discharge questions

[BirdRock]

Bought a 2009 Marlin and trying to get out head system completely operational. Survey showed that the breaker would trip when the head was turned on at control panel. We replaced the pump (shown in first photo) which was located behind panel on port wall in the aft bunk area. Head now works perfectly and drains into the main waste tank.

Was 30 miles offshore last week and wanted to see if tank would discharge and drain. Had the manual with me and followed instructions. Opened seacock, turned on head, water pressure and holding tank discharge switches on the DC Panel. Then went into the head and turned the key to start. Nothing happens.

I see a 2nd vacuum pump (2nd photo) that sits on the main tank and is between tank and thru hull where discharge should flow. I assume this pump isn’t working either but other than replacing not sure how to confirm. Any ideas?

I did go to the pump out station at the neighboring marina and that worked perfectly so emptying the tank isn’t a problem. Just wondering why I couldn’t get it to discharge as an option.

 

[Meanwhile]

Following.

 

[wspitler]

There are two pumps. One for vacuum and one for discharge. They are both similar diaphragm type pumps and duck bill valves. There is also a seacock on the discharge that needs to be open. Most common problem are the duckbill valves. If the pumps are running and you can see that by removing the cover, most likely bad duck bill valves. Not hard , but messy to replace. 4 on vacuum pump, 2 on discharge pump.

 

[Fishtales]

Was the tank monitor operative pre and post trying to pump out? I've never had a prob with mine so watching this....

 

[BirdRock]

Was the tank monitor operative pre and post trying to pump out? I've never had a prob with mine so watching this....

Yes. Showed empty when we purchased then full after we used/tested system multiple times after replacing the first pump. Now shows empty again after we pumped out tank.

 

[BirdRock]

Thanks wspitler!

 

[Beyond A Wake]

Had the head been used by prev owner? if it was left sitting with crap in it it may be the macerator pump? Diaphragm only no macerator? has frozen and needs just a proper "wiggle" help. Disconnect motor from pump as it seems motor is not running, the try to rotate shaft with a wise grip or similar. then try again....... . Then try to see if diapfragm moves, if yes try to source a new motor etc....
Of course it may be easier to just replace the pump/motor assembly.
just my 2 c

H

 

[glacierbaze]

Every thing has a plug in, right there at the tank. Before you buy another pump, make sure you have power to all those plugs when you are supposed to, and that the connections are clean.
I think macerators have a hex fitting on the end, like on the bottom of a garbage disposal, to try to clear any log jams, without taking anything apart.
That looks like your trim tab pump/reservoir on the right bulkhead, in the first photo. Doesn't look like any fluid in the bottom tank.

 

[georgemjr]

First see if pump is moving when you turn the key. Yes moving = problem with either diaphragm or duck bill valves as mentioned. No, not moving = either problem with electric getting to motor or motor itself. Check with test light at the plug near motor if you are getting current. Yes = problem with motor. No = likely problem with control panel or if not, wiring.

 

[Legend]

My Sailfish had a similar issue in that ir would blow a fuse every time we attempted to use it. Turned out to be a couple of dimes caught in the maacerator blades. Removed the coins and not more issues with power blowing out.

 

[georgemjr]

That set up does not have a macerator. It simply has a bellows pump out run by a windshield wiper motor.