From your previous post regarding your diff, it seems you have a 2009 4/4, but don’t know your experience with Morgans.
As John says, check that all 4 heater louvres have been opened (by hand) Also note that the heater knob and mechanism can be very stiff and full output may only be achieved if you rotate it to at least 4 stops or even 5. Morgans tend to run a little cooler with an Ali rad anyway, but even at an indicated 70 or so, you should be feeling the heat.
