I've had the heater core flushed, replaced the thermostat and put all new anti-freeze in. All of the hoses are getting warm. Just put in a new water pump & a/c compressor 4 months ago. It did work fine for a while after that so don't think that caused any problems. The temperature gauge does not get far off the "C". (Kind of goes up and down but never to the halfway mark.) I've driven it for literally hours and it still doesn't get warm. Any ideas?