Water pump won't pressurize, maybe a clog?

[paulg222]

So on my 1999 Catalina 42 MKII, my water pump is occasionally not pressurizing and sounds maybe like it has air in the line (makes a different sound when it is actually pressurizing with water vs what I interpret as air in line sound).

I can sometimes get it going again by leaving the pump running and opening the sinks, etc. But this takes some time and doesn't always work. I usually try for a while, give up and then after moving the boat around/sailing try again and it has worked a few times after that.

I think I have a bunch of algae or something that could be causing the issue because my filter by the manifold (which let's me switch which water tank to use) was badly clogged, and I cleaned it out (bunch of white gunk).

Is it possible the gunk got past that filter and into the water pump itself or in the line downstream and is causing a problem? Not sure. I mean I can see that water is reaching the filter and next stop from there is the pump, so I'm not sure what the issue is as pump is roughly level or lower than that filter so water should not have an issue flowing.

Should I disconnect the hose from the filter to the water pump? It looks like I have some pex tubing or similar, with these white fittings, not sure if they are quick connect/disconnect kind or not but I'm hoping they are. If so I could try to disconnect and just clean out that line or investigate. Fortunately the manifold has valves so I can turn off all the water supply first.

Any other thing to try?

[HUFFnPUFF]

turn off your water pump and pull it out. Usually 4 screws to remove it. Mine has quick disconnects on the hoses so its easy enough to pull and take a look. At least you eliminate a potential issue. I would also check your prefilter and see if that is dirty. The prefilter sits in front of the water pump and should be right next to it.