I have a fresh water cooled 8.1 liter gas engine in my Carver yacht. I serviced the seawater impeller and seawater pump. Water drained out when I did this. At first I thought it was just seawater, but do you normally top of the fresh water system when doing this job? I added a gallon of distilled water in the freshwater heat exchanger, but the engine seems to still get hot and makes warning beeping sounds. Should I fill the heat exchanger to the top with freshwater? Is there something else I should be doing?
I'm in agreement with mike. open up both sides of your cooler and wash it out with a hose. make sure that there is no debris from the old impeller stuck in the veins. check both sides, intake and outflow, of the pump for dbris too as sometimes it can get blocked if your impeller chewed itself up. there should be a blead screw on your cooler/heat exchanger, open it enough to allow the air to escape and start up your engine. if water starts to spray out then tighten it back up, problem solved. if not then you have a blockage further back somewhere. also check your strum box for debris and make sure your seacock is open. if you've checked all of this and the problem persists the splines on your pump might be stripped.
Fresh water is antifreeze not distilled water and it needs to be full. Now if you lost antifreeze when changing the impeller you have a real problem since the two systems are not connected and yes the heat exchanger needs to be full - heat is transferred from the antifreeze to the raw water to cool you engine. Your antifreeze overflow (like the one in your car) should be filled to the cold level when the engine is cold and with radiator cap off (you boat doesn't actually have a radiator that's what the heat exchanger is) it too should be full of antifreeze. Next what condition was your old impeller in? Was it whole or pieces missing? Missing pieces can block raw water flow through the heat exchanger.
First your boiler is a GAIA 424/8 S or RS do not recognize the form off hand yet maximum combes are very a lot alike. do not recognize were you obtain Knightsbridge from. Your difficulty appears like a diverter valve diaphragm at fault. With the critical heating became off, look on the valve unit (large brass block 3 large pipes and a couple of small ) on one end is often fixed a change block (black in shade) that is actuated by technique of a pin that is pushed out from the valve even as the nice and cozy water tap is became on, is this operating if not then its the diaphragm. utilising a small screwdriver gently perform the micro change does the boiler stir up now. If sure then the electronics are ok.
You are dealing with two separate water circulation systems,and I doubt that your problem is the fresh water side.Did you reopen the raw water sea-cock?Open or not, I would have to reinspect the raw water impeller.Drive pins,keys,etc. in place? As Ned suggests,were some of the impeller vanes missing or was this a preventative maintenance job? If pieces were missing they may have stopped up an oil cooler or the heat exchanger.Carefully retrace your steps and you will find the problem.
