I have 2005 c230 kompressor And i just wanted to know why does my car take long to warm up, I just changed the therma stat not too long ago?

 

All depends on what you mean by "a looong time!"

Small engined vehicles (especially those trying to be "eco") put out limited heat from the engine since Heat to cooling system = Wasted energy
A small diesel vehicle can take "forever" to warm up in cold weather at town speeds.

So what are you comparing the warm up time with. An S500? LOL.

I suspect that your ambient temp is low, you are driving at limited speed i.e. 30mph and you are use to something less gas mileage concious.

However, since an effective heating system is a requirement the engine coolant thermostat endeavours to keep what heat is rejected from the engine within the engine block, at least until the thermostat open temp is reaached.

Since you have already changed the stat (I will assume the replacement was a good one (OE?) and with the correct temp setting) I suspect that your heat availability expectations are greater than the engine can supply.

As another possibility maybe the engine is warming up correctly but the duo valve that permits hot water into the cabin heater is not opening correctly.

Duo valves do give problems and stick. You can open them up and remove any corrosion / lubricate.Determine if the tubes going to the heater AFTER the duo valve are hot.

Stuart