Jammed Purge Pump

[YVRguy]

Hello all;

We seem to have a blockage in our waste system on our Hunter 34. I need some advice on the likely location of the blockage so we can focus our repair efforts. We can pump the head itself no problem so long as there is room in the holding tank, although it seems to emit a strong odour with each flush. The main problem is that the purge pump we use to empty the holding tank when at sea is stuck fully open. The pump can't be used even with significant force. We assumed this was because the tank was over-full so we went to a pump-out station and emptied it. The purge pump worked for a few pumps and then jammed, even though the tank is empty. it's hard to say whether it's a physical jam or simply air pressure keeping it open. Any thoughts are appreciated.

 

[jssailem]

To clarify, you have an open valve to the sea. You use a manual pump to pump waste from the holding tank to the sea ( you state pump can’t be used even with significant force). There is a Y valve controlling the direction of the waste from the holding tank to either the sea or the pump out and you have it set to “sea”

Further you have emptied the holding tank by using the pump out. You are able to pump clean water into the holding tank from the head. So no blockage between the head and the holding tank.

Do I understand this correctly?

 

[dlochner]

Where's Miss Peggie?

The hoses smell which tell me they are old. You're pumping overboard, so you are in salt water. If this is a manual pump or even if it is a macerator, I suspect the hoses are clogged with calcium and the ID is not longer 1.5" and is actually much smaller. When it is time to pump overboard, the hose quickly clogs with TP or whatever is in the tank. The solution is to replace the hoses and clean the valves and rebuild or replace the pump.

To give you an idea of how clogged the hose can get, here's a photo of my Y-Valve before I cleaned it.

 

[YVRguy]

To clarify, you have an open valve to the sea. You use a manual pump to pump waste from the holding tank to the sea ( you state pump can’t be used even with significant force). There is a Y valve controlling the direction of the waste from the holding tank to either the sea or the pump out and you have it set to “sea”

Further you have emptied the holding tank by using the pump out. You are able to pump clean water into the holding tank from the head. So no blockage between the head and the holding tank.

Do I understand this correctly?

Yes, that's correct. We can empty the tank either by pumping out manually at sea or doing an external pump out. There is no valve controlling this (that I'm aware of). Suddenly the manual pump has jammed.

 

[YVRguy]

Where's Miss Peggie?

The hoses smell which tell me they are old. You're pumping overboard, so you are in salt water. If this is a manual pump or even if it is a macerator, I suspect the hoses are clogged with calcium and the ID is not longer 1.5" and is actually much smaller. When it is time to pump overboard, the hose quickly clogs with TP or whatever is in the tank. The solution is to replace the hoses and clean the valves and rebuild or replace the pump.

To give you an idea of how clogged the hose can get, here's a photo of my Y-Valve before I cleaned it.

Thanks. Yes we have seen that kind of build-up as well. I guess maybe we need to just keep replacing hoses until it works

 

[dlochner]

Thanks. Yes we have seen that kind of build-up as well. I guess maybe we need to just keep replacing hoses until it works

While you have everything apart, it might be a good idea to rebuild the pump. I'm assuming it is a diaphragm pump, probably a Whale. Eventually the bellows wears out and the 2 check valve flaps also wear. If the hoses are calcified, the pump is too.

 

[Peggie Hall HeadMistress]

Thanks. Yes we have seen that kind of build-up as well. I guess maybe we need to just keep replacing hoses until it works

Nope... If the pump jams, problem is most likely in the pump. If you never rinse it out after use, it's most likely clogged by a buildup of the animal fats in waste and waste those fats collect...or possibly a wet wipe. (NEVER FLUSH A WET WIPE!!) Unlikely to be just TP unless you're flushing premium TP instead of quick dissolve TP which dissolves in water in an hour or less.

The tank, pump and overboard discharge plumbing should be rinsed out after every use...or at least after several uses. To do that, pump out the tank then use a hose to put a few gallons of water into the the tank via the deck pumpout fitting...flush that out using the pump.

That's how you PREVENT this problem...since the pump is jammed, curing it will require opening up the pump and cleaning it out by hand...and, depending on the age of the pump, rebuilding it.

If you also have stinky hoses, replacement is the ONLY cure. It doesn't have to be a nasty job...My book (see link in my signature) has step by step instructions.

--Peggie

 

[YVRguy]

Nope... If the pump jams, problem is most likely in the pump. If you never rinse it out after use, it's most likely clogged by a buildup of the animal fats in waste and waste those fats collect...or possibly a wet wipe. (NEVER FLUSH A WET WIPE!!) Unlikely to be just TP unless you're flushing premium TP instead of quick dissolve TP which dissolves in water in an hour or less.

The tank, pump and overboard discharge plumbing should be rinsed out after every use...or at least after several uses. To do that, pump out the tank then use a hose to put a few gallons of water into the the tank via the deck pumpout fitting...flush that out using the pump.

That's how you PREVENT this problem...since the pump is jammed, curing it will require opening up the pump and cleaning it out by hand...and, depending on the age of the pump, rebuilding it.

If you also have stinky hoses, replacement is the ONLY cure. It doesn't have to be a nasty job...My book (see link in my signature) has step by step instructions.

--Peggie

Thanks for this. I'll check out your book!