issues with CR220

I just purchase the CR220 and install last night but I'm having issues with it. The lid will leak out water after i open the outlet valve to recirculate the water. It usually takes a couple of seconds when the pressure builds up then the water leaks at where the seal is at top of the lid. I tried to retighten it and it still does it. The rubber washer or gasket is there and it is as tight as my hand can twist it and still leaks water when i tight it. Can you let me know if I'm doing something wrong? It does not seems right as the pressure should not cause for it to leak like that. Please advise, thanks!

Vong