Minecraft Tinker's Constrct Smeltery isn't working?

I just started fittle-farting around with Tinkers Construct today after hearing good things about it. The only problem is when I go to put lava in the seared tank it won't let me. It just places the lava on/above the tank. I tried shift clicking and all sorts of stuff and it's still not working. I know I built the smeltery right because the controller is lighting up like it's supposed to when you built it right. Anyways, anything will help. If for whatever reason we can't figure it out, I'll just re install the mod and see if that works… Thanks!