I just replaced power steering pump....and seem to have poked a pin hole on the radiator. Impatiently
..I dumped some Barrs stop leak....let it run....stopped the leak...and had heat. NEXT MORNING....heat guage went up to normal reading but fan blowing cold air....warms up a little bit....but still cold. Guessing thermostat stuck open and replacing today.....but....thinking....stop leak could possibly clog heat exchanger.? Any advice appreciated....
Roving in Maine USA....5 degrees outside.

 

Stop leak sucks. I grew up in a radiator shop/restoration shop and hated that gunk.

I dont believe your thermostat is bad, you may have air.

people are too quick to jump to the thermostat and spend money.

park your truck on a hill and bleed it.