I have a dometic PML 500L water...

[DJH]

I have a dometic PML 500L water pump that cools my Cruisair Air conditioner. I hear the pump running but there is no water flow. I think the impeller is fouled. This happened a couple of years ago and I watched the technician clean it off and then reassemble it. It seemed pretty straightforward and I am thinking of attempting it myself. Any suggestions/Instructions would be welcome.

[Korkie]

Make sure it didn't just lose its prime. These pumps are not self priming. There are several ways you can do this. The way I do it is back flow water from the discharge (thru hull). You will need an adapter that will fit in the hole. Turn water on, not real strong stream, hold there for a minute and then go retry your AC. To clean it, just take the pump housing off. Be careful as most of the them are plastic and can break easily. Clean everything up and re assemble. Will still need to re prime. You should flush it out well at the end of the season with fresh water. I run Pine Sol into mine and let it sit for an hour or so and then flush with water and then pink antifreeze or blow it out with air for the winter. Just a few options. Good Luck!

[DayTripper]

Make sure the outlet is not clogged mine was by a mud Dobber wasp

[Seabuz]

Lorikeet is right. I have to prime mine at the start of every season. Shut your thru hull off, then take the hose off the discharge side. Now open the thru hull a bit once the water comes it would be primed. I also blow through the hose to make sure nothing is clogged. Reattach the hose and you should be good.

[RMS]

not sure of the age but assume it has a seacock - make sure it is open, and if it is open make sure the screen has been cleaned recently. it could also be the problem. if you are cleaning the screen make sure to close the seacock first. there are lots of youtubes on this that will explain better than me. good luck

[Korkie]

All of the above will prime it. Back flushing will prime it as well as clear any thing that is on the filter, if you have one - most do not, and is no mess in the bilge to clean up. Been using this method for three boats since 2002. Ez Pz.

[Reddog]

I had to prime my system before it would work this summer. I put a shop vac on the outlet with the AC pump running and it sucked the water thru. Works fine now!

[beau1]

Agreed. Especially after she sat on dry dock for awhile. I put water thru the ac drain on side of the boat then the pump will work with water in the line.