While we are waiting for Peggie to respond to the alarm I have a
suggestion. Get a rebuild kit for your head, get out your tools, and
start taking it apart. These are very simple and straightforward
devices. If taking one apart and putting it back together is beyond
your mechanical skills, you are going to have a lot more significant
problems living on a boat.

Even if the head turns out to have a fatal problem such as a scored
pump cylinder, knowledge of its inner workings will greatly improve
your ability to deal with future problems. A heavily used head on a
live aboard boat probably needs a rebuild kit installed every year or
so anyway and this is quite likely to solve your problem by itself.

While it's apart, make sure the inside of the pump cylinder is smooth.
Slather the piston and the inside of the cylinder with Teflon grease.
I found it most easily at a bicycle shop. The auto stores just gave
me blank looks.

--

Roger Long