Originally Posted by preservedkillick
My question is this, does the expansion tank need to be higher than the engine's heat exchanger?
You question was this, was it not???
My answer was Yes it does...what else or how was not this to your sufficience??
You then don't like my answer???
I know BY EXPEREINCE it does need to be higher..
When we installed my engine a new Yanmar in my boat, the water heater was installed by Vetus, and for weight balance we needed to install it in the stern which is higher than the engine..
Because the expansion tank wasa lower, the engine was allways hot, and sounding the alarm, as the water heater was behaving as the expansion tank..
We moved the tank one foot higher and fixed the issue...
The Yanmar installation manual (the ones Yanmar installers have, not the owner manual),clearly indicates the location, distance and height...my case was a lapse because the heater was installed higher..