When I'm cruising at 1200 to 1300rpm my calorifier heats the water perfectly but when i'm moored and using the engine at 900rpm or so for battery charging the calorifier water doesnt heat up.
It has been suggested that maybe the engine water pump isnt pumping the hot engine water around the calorifier at that engine speed ? There are no restrictions or air locks in the system.
I have spoken to others who dont seem to have a problem at battery charge engine speed so I'm lost as to what it might be.
Has anyone any ideas how I might cure this please.
Thanks everyone
JULES