Earworms wrote:
The sign is poorly written so I'm not sure exactly what they are trying to say. As I read it, hot water comes out of the cold tap for the first couple of seconds. Sounds as if the cold water pipe is situated near the hot water pipe or the hot water heater which transfers heat to the cold water running in the bathroom sink.
What is a Hot water heater (that you mentioned) supposed to do? if the water is already hot it does not need heating.