Random Airlock?

[Takeshi]

Drove the car last night and and looked a the temperature gauge and noticed it was up higher than normal, I know myself it barely comes up from the bottom in this cold weather. Put my hands in front the vent and, no heat

 

Stopped the car and the radiator was cold and the hoses so I pulled the cap off and water boiled over. Put the cap back on and started the car again and it was running hot, but the hose from the manifold to the heater matrix was stone cold. I drove back home, engine was hot but never boiled over. Let it rest for a bit then pulled the cap off and water everywhere, I'm impaitent

 

Filled it back up and its ok now. I didnt use it on Monday so, it either froze up somwhere in the water system, or a air lock appeared. Aint fiddled with cooling system for a good couple months, thought sometimes I could hear burbling from the heater box.

 

Any suggestions? Odd how it just randomly done it.

[Chris!]

mine froze up yesterday, it was colllldddddd