I drive a Mercedes C180 Kompressor. No matter how long the engine runs for the heater never really seems to get hot. Is this normal and is there anything I can do to remedy this?
I agree with RATTER15. Thermostats are designed to fail open these days. If the temp gauge never reaches normal this is likely to be the problem. If the temp gauge does reach normal you may have an air-lock. Try giving the hoses a sharp squeeze with the engine ticking over and with the radiator cap off. Be carful of where you put your hands.
Replacement of a thermostat was traditionally a 5 minute job and cost £2.50, not knowing the placement of the thermostat on your car specifically it could well be a bigger job, either way it shouldn't be a huge expensive job.
sort out the problem rather than bypass it with an additional heater, damage will occur to your engine if you continually run it cooler that it has been designed to run.
wouldn't bother with the ceramic heater - i got 2 years ago thought it would help defrost the car before i set off -15 mins later a small clear patch cleared, when you drive off it flies off the dashboard.
I bought a new Rover 214SLI during the winter of 1992. The heater was rubbish. The needle only reached normal in a traffic jam. I took it back. They told me that no thermostat had been fitted from day one. It worked perfectly afterwards. Despite what people said about Rover it was one of the best cars I owned, it never let me down in 8 years..