If you run a 240 v genset seawater cooled mine is a Fischer Pandair 4000 this time of year there is lots of floating weed around that clogs the inlet filter do the filter clean daily ! or every time you turn the gen set on !! I was lazy and left it 2 days! Clogged filter, gen set shut down so
1. Cleaned filter clogged ! [ still shut down again hot] mine has various safety systems
2. Replaced impella all blades stripped count the blades ! Important [ still shut down again hot] lube with Vaseline
3 Back flushed water system [still blocked]before exhaust! Do not back flush with water it can fill the cylinder through the exhaust [ Use compressed air if possible ] if you have it! Me being a diver and gear always on board [ but ... still blocked!
4 Remove sacrificial anoid and Bingo some of the minced impella blades were blocking one port! normally they will be broken up enough to pass through but ..... not so lucky this time. So fit an expansion box with large particle filter trap after the pump and before the Airbleed
5 Start gen set [Take shower] then tell yourself off for being lazy! and or stupid. Large glass of red or chilled white and go back to enjoying yourself
P.s Fischer Pandair also recommend removing the thermostat if one is fitted and throw it away it's not needed!
Gen set back to it's happy self, chuntering away in it's cupboard!