Our Spider (1984 - S3) has quite a good heater. It has a 180F thermostat, the temp gauge reads about 180F and the heater will warm up the ****pit quite well.
I don't recall the shop manual's instructions off hand but when I had the heater out I did it when I also had the dashboard removed. Although that makes it sound daunting it really is not. Most of the time spent to do that involved removing the center console & numerous electrical connections.
The Alfa heater is also known for having its blower motor sieze. The motor sits at the very bottom of the heater unit thus any water/coolant that gets in there has a bad effect on the blower motor.
I don't recall the shop manual's instructions off hand but when I had the heater out I did it when I also had the dashboard removed. Although that makes it sound daunting it really is not. Most of the time spent to do that involved removing the center console & numerous electrical connections.
The Alfa heater is also known for having its blower motor sieze. The motor sits at the very bottom of the heater unit thus any water/coolant that gets in there has a bad effect on the blower motor.