I just replaced my thermostat and coolant temperature sensor because I was having some issues of the engine overheating, and also not being able to get hot air into the car.
The car would over heat when i've been driving then am sat still for 5 mins or more, the engine temperature would rise and then the cooling fan would kick in.

So now, I've replaced the 2 parts, and refilled with coolant, now I don't know what this problem is.
I started the car and let it idle for a while, while keeping an eye on the coolant level.
Then all of a sudden steam starts coming out of the fill hole.
Even with the cap on, steam pushes its way out. The engine heats up to almost red, which i've never had before and then the cooling fan kicks in, which is also very late compared to normal. But it doesnt make any difference at all! The temperature just keeps on rising. So I turned the engine off for a moment, then slowly started undoing the cap letting all the steam and build up of pressure out.
If I do it too fast, the coolant just boils over the top.

Will a faulty heater control valve cause it to over heat or anything?
The right hand pipe that goes into the hcv is hot, but all the others are cold.

Also, the pipe that goes into the right hand side of the expansion tank, then to the right side of the engine block, when I turn the engine off, it bubbles alot, what does this mean?

I really don't know what I'm doing wrong.

Please help!