Forgive me for bringing this one back to life, but I just wanted to clarify something. I am having similar problems with the spring moving the weight. When I heat it, the 'arm' of the spring stretches back from the peg, but the flap/weight doesn't move. It moves very easily by hand though. My question is, should the counter-weight always be working against the spring and trying to close the flap? If it did, then I would expect that it would work as it should. Any fixes to getting the weight to put more pressure on it? Perhaps some sort of lube? What can take the heat? Thanks!