2002 Jaguar S-Type heater blowing but not heating

Hello melissa it sounds that your thermostat is stuck open have replaced goodluck please rate

There is a 98% chance it is your electric heat pump. Because Jaguar uses the closed water circulation method. Now the heat pump primary function is to supply or pump coolant to the heater core at low rpms or at idle. Once the heat pump fails it can actually block or significantly slow the flow of your coolant. I have fixed around 20 Jaguars with heat related problems ( xjr,xj8,x-types,s-type) all had a bad or very dirty heat pump. 5 of them i was able to clean the rest had to be replaced. Note... a bad heat pump can create a back pressure which in turn force or push coolant out at the connection (a small 3 way coupler) located at the bottom of the coolant reservoir tank given you the appearance of coolant leak. I mean you will have a coolant leak but once you replace the heat pump the coolant leak at that coupler will stop. Also back pressure can stop the coolant flow blowing your intake manifold or head gaskets.