This is my first Honda and was wondering are their heaters really poor, or have I got a duff one. If I sit with the engine on and not move, the heater is fine, and the needle on temperature gauge will rise up about 20mm after about 10 minutes. However once I drive off the needle will drop and the car will feel cold again. Anybody any ideas why this is happening. It's a 2001 civic sport by the way.