If you water allows him to drag his wattles through water every time he gets a drink that could be the porblem. Because his comb would be wet and then either get cold or even start freezing. Just some thoughtsI can't wait to see my RC leghorns.
The big single combs get frost bite too easily.
My Marans rooster looks like he already has a little frost bite on his wattles and his comb, just from this fall. I really didn't think that we had been that cold yet.....and his coop has good venting...odd really.
So yes, I am wanting to switch to only little combs.