I have a '97 414, and 2 months ago I started getting serious condensation on the rear window. At times it looked like I'd sprayed the window with a hose.
At the same time the heater didn't warm the car like it used to. It was as if I had the ventilation set to recirculate.
Both problems were solved (sort of) by opening a window.
Where on the Rover are the vents for stale air, as it looks to me like they must be blocked.
Condensation
The vents are in the boot behind the trims (near the boot light)
Also check for leaks into the boot area. The rear lights and the vents are common leak areas.
Also check that the fan's recirculation flap is working correctly. This weekend I found out that the flap on the car in the forum banner had fallen off. It had unscrewed itself and fallen on to the top of the motor. This made the fan poor and it constantly recirculated the air, until you got to high speeds and then the passenger got a cold draught from outside the car. Simply re-attaching the flap sorted the problem and now the heater is back to full strength. (It still has some small boot leaks though :()
Also check for leaks into the boot area. The rear lights and the vents are common leak areas.
Also check that the fan's recirculation flap is working correctly. This weekend I found out that the flap on the car in the forum banner had fallen off. It had unscrewed itself and fallen on to the top of the motor. This made the fan poor and it constantly recirculated the air, until you got to high speeds and then the passenger got a cold draught from outside the car. Simply re-attaching the flap sorted the problem and now the heater is back to full strength. (It still has some small boot leaks though :()
