i have the same problem i have to open the valve by hand, it is in the drivers side footwell on the left hand side. even then it does not get really warm but the difference is noticable
Ian Swinnerton, November 2007
Possible reasons:
1. The engine may not be getting hot enough. Check if the thermostat has been removed for some reason, if the thermostat is there put it in some boiling water. It should open and then gradually close as the water cools.
If it stays open fit a new one.
2. The small radiator inside the heater (known as the matrix) may be blocked with dirt and restricting the flow of hot water. Try flushing it out with a hose pipe.
3. The temperature control on the dashboard may not be working properly. Look under the dash whilst operating the control and check that it is fully moving a lever on the heater unit.
