mermaid AC no water

[Sailor John]

Good day all
I am asking for my friend Frank, who doesn't have a Hatteras, but still has a problem.
I'm trying to resolve a glitch with Frank's 12K Mermaid AC. It has no water coming overboard when it runs.
The 12 volt water pump works well with lots of water being pumped into the bottom pipe of the AC unit, but there is no water coming out of the top pipe of the unit, then overboard. Is there a valve within the pipe that is not opening? I even tried a 'backwash' by reversing the pipes, with no luck. I tried mermaids web site, with no luck, and have sent them a, as yet un-responded-to email. I could not find this specific issue on the HOF.
Any thoughts would be appreciated.
Sailor John

[rsmith]

It's plugged up with crap!

[Sailor John]

You know, sometimes, things just work themselves out. I visited my friend Frank's boat today, turned on the AC, and the system worked perfectly. Go figure.
Maybe there was ice in the line, perhaps something else, who knows; but it's working now. I think I will buy a lottery ticket tonight.
Thanks!
Sailor John

[Pascal]

The coils in which the water circulate can't ice up... It s likely that some growth or debris was plugging it.

I ve also had issues with shell bits getting stuck in discharge lines. If you re going to back flush, you need to disconnect the hose at the AC and put it in a bucket so that whatever was in the hose, doesn't end up in the coil just to flow back into the hose when you restart

Another common issue is a plastic bag stuck in the thru hull inlet. With the pump off you will have water flowing in but once the pump kicks in it pulls the bag tight and cuts the flow.