Is this pump self-priming

[wufibugs]

I'm relocating my overboard pump and wondering if it has to be installed lower than the holding tank or if it will self-prime when pumped.

 

[Ukeluthier]

Can't speak for that specific model, but diaphragm pumps are normally self-priming.

 

[Calif. Ted]

Looks like a diaphragm pump to me and as such is a "positive displacement" pump meaning it will "pump" both air and water and therefore self priming. You could always attach a hose to the intake run to a lower bucket of water. The diaphragm is rubber and there's a couple one way valves that may need service.

 

[Ralph Johnstone]

I'm relocating my overboard pump and wondering if it has to be installed lower than the holding tank or if it will self-prime when pumped.

I have one stored strictly as a standby pump for the possible failure of the holding tank macerator pump. It took a prime easily on the one test I did. The lift there is about 5 ft. to the deck pump out.

 

[woodster]

that looks like a bosworth/guzzler brand pump and it will pump without priming it

 

[Gunni]

test it. These pumps sit unused for years and the diaphragm and check valves go bad. Don't want that when you really need it.

 

[caguy]

test it. These pumps sit unused for years and the diaphragm and check valves go bad. Don't want that when you really need it.

.
Especially with what he will be pumping.

 

[wufibugs]

Woody, it is indeed a Guzzler. Good points about checking the valves and diaphragm before installing. I will disassemble, clean [ugh] and test. Pump is only about 15" above the height of the holding tank outlet. Ralph, why would you pump up to the deck cleanout? I only use the pump to discharge overboard down to the thru
hull below the waterline. [where permitted, USCG lurkers]

 

[Ralph Johnstone]

Ralph, why would you pump up to the deck cleanout? I only use the pump to discharge overboard down to the thru
hull below the waterline. [where permitted, USCG lurkers]

As mentioned, the standby diaphragm pump is stored in the bottom of a lazerette waiting for the big day when the macerator pump decides to fail. When that day arrives (which will be the first day of a one month cruise) I can then go to the deck cleanout and attach the standby pump and pump out the holding tank. There is the suction side of the pump which is pulling from about 5 ft. below from the holding tank and then the discharge hose which goes over the side and down into the water. The negative suction head is balanced by the negative discharge head and the pumping action is quite easy. Also, the discharge hose going down into the sea water tends to eliminate the spray in high winds :cussing: :cussing: :cussing:.

I have only tested the pump once and it works well.

 

[wufibugs]

Got it. You are using the spare in place of the clean out dock should the primary pump fail to pump the goo through the discharge thru hull.