Do you have 4 hoses going to your filter? if so, it has the preheater. If it's only 2, it dosent have it.
Thanks, I'll take a look, I'm pretty sure it has more than 2. So is that for coolant heating or how does the heating take place?
I believe the heating takes place by using the warm/hot re-circulated diesel (the return line should go through the filter, and back into the tank)