Land Rover Repair: heater, water pipes, rangerover

Question
My heater on my 99 rangerover would blow cold air through vents and then it would heat. I thought it was the termostat and replaced it but it still blows cold. I just noticed that the floor mat on the passinger side is wet near the door . What should I do

Answer
The floor mat is probably wet from leakage of the seals between the heater core and the hot water pipes.

The hot/cold issue sounds like failing servo motors but you need a test system to check that for sure.  If you run the dials from hot to cold and the temp only changes on one side, that's a near certain indication of servo failure