Heater issues
 

My son rolled the truck...just a little. Among the issues we now have is that the heater does not work. I don't know what the roll over could have done. I need some help. We did check coolant levels...all hoses appear ok. There is a slight temperature difference between the 'cool' setting and when you turn the dial to the warmest setting, but not much.

Would a good flush and fill accomplish anything??

I really don't know about the heating system. I can easily replace the thermostat, but can't think of why that might be necessary. A friend mentioned the 'sending unit' but was not sure if that was related to the heater. Any help would be appreciated.

What year is the truck

According to his profile it is a 1997 F150 4X4 4.6L V8

Maybe the crash caused the thermostat to freeze up...............

I think I got lucky. I did a thorough flush ( not direct, just the system). I put the water and flush in and drove it for several hours over 2 days..plus kept it in the Garage overnight to keep it from freezing. I noticed that the heater was a LITTLE warmer after the water flushes, but still only one Heater hose was hot, the other barely lukewarm. I thought i would have to do the Direct Flush by removing the hoses. BUT on the second day I noticed that when I revved up to higher RPM's I heard a gurgle sound like air and water from the heater core area...something was breaking loose. I drove it for another hour and a half and that noise got louder, like running water now and then and then slowly subsided. The heat was getting hotter by the minute so I guess the flush and the flow broke something loose. I flushed again and put 50/50 back in, and now I have good heat. I guess the roll over must have either got a lot of air in the core or some rust or something lodged on one side. Now both hoses are hot and all is working well.

Thanks for the suggestions.