Heater goes hot , cold and back to hot.

The issue I'm experiencing is my heater goes hot...melt your face hot, and then after about another 5-10 minutes it starts to cool down and then it goes back to hot. Now, I don't hear any clicking sounds and I have yet to check the level in the radiator. I will do this in a few hours after it cools down. Just wondering if it could be the t-stat if the radiator is full? Any ideas welcome here.


Thanks in advance.

Could be an air pocket in the lines somewhere, if you run it all the way hot it should suck coolant from the backup Res.

Run the system from cold and note any fluid level changes once warm

Air pocket or low on coolant. Is it cool at idle then gets hot when u rev up on the engine?

I figured it out. The radiator is leaking...low coolant. I couldn't check earlier because it was dark out. Sick of this crap happening right when it get's cold outside. Frustrating!!! Thanks fellas.