My civic use to blow hot air but my climate control switch from hot to cold has been snapped off
recently as I tried to slide it from cold to hot (which use to work) the arm for the control sprung back from hot to in the middle
now my car blows room temp
regardless I have taken the cable to the heater valve under dash and disconnected and manually pushed my valve open it moves quite a bit but i cant tell if it's all the way (dont want to force and break stuff)
any tips or recommendations on how to fix the heater was working great until the arm on the climate control sprung back to middle

 

That lever only moves a small distance, you might have to take a closer look at it to see the range of its path.

 

i had this issue where i would slide all the way to hot but it wont stay all the way in the hot position. i fixed this by playing around where the cable runs below the glove box. there is a clamp that holds the cable at the end there.. where you clamp it on the cable is how you fix it.

 

If you move the lever on the bottom of the box all the way forward (and as @triple beam points out, make sure it stays there) you should get heat. If not the next thing to check would be the coolant level-- look in the radiator (when cold) and make sure it is all the way full, don't just check the white plastic tank. Also the cable operating the water valve on the engine side of the firewall should move when you move the hot/cold control lever.