Macerator Pump only pumps air

[Passages]

Looks like there is a target date to reopen the Bahamas of July 1.

One of the critical systems that needs to work over there is your holding tank macerator as pump out stations are few and far between. Mine has not worked for a few months but Stateside, I don't really need it.

Anyway, my macerator pump cycles, but only air is discharged out the seacock. Tank level never changes. When I grab the sanitary hose, it feels like something is moving around in there but when I look over the side, all I see are bubbles.

So my thoughts are:

Bad hose from holding tank
Blocked hose (but why would air pass)
Bad diaphragm in the pump
Bad anti syphon valve.

Before I dig into this REALLY nasty project, thought I'd bounce it off you guys.

Any ideas?

 

[MadHatter53]

I have a valve before the macerater pump that needs to be set for the mace to draw from the tank.

 

[Passages]

Fixed it!

It needed prime. I have not used the pump since last year. Feed hose was dry. Took off hose end, filled it with water, reattached and voila!

Perfect example of how sometimes the best thing to do is take a break, do something else and like magic the solution is there.