I have a Refleks diesel heater, it has never performed well on my boat, a friend has an identical heater and my "full" is more like his "half" or less. I have tested the fuel flow and I get 1 litre an hour arriving at the carburettor, which is the maximum the heater is supposed to burn on full. However, the float is not really afloat at all, indicating the fuel level is too low. Even if I remove the needle valve which cuts the fuel off, no difference. All filters clean. If I top the float chamber up manually though the heater roars away like it should on full. So I seem to have a float level problem rather than a fuel supply problem - any ideas?