Sorry my vivaro water heater unit is getting very hot and smoking when i have van running for a few mins.
temp gauge not showing any reading but when heaters switched on its only blowing cold air. the heate runit is under the bonnet with 4 grouped pins help ,,,,,,
I know there is a housing on these with four pins on with electrical connections but I don`t think it is a heater but more like a thermostat housing,sorry a while since I was on one of these,but i would check if your top rad. hose is getting hot,if not see if the thermostat is opening
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix vans.