To solve problems on a remote controller 1 for controlling a water heater 2 from a remote place that as it is generally fixed to a wall surface and the like, a user must go to the place where the remote controller 1 is installed to perform any operation, and further in a case when a wireless movable cellular phone 3 is used as the remote controller, and a wireless signal from the cellular phone 3 is relayed to the fixed remote controller 1, it is necessary that an operator operating the remote controller 1, is prevented from having uncomfortable feeling.

A light receiving portion 11 capable of receiving an infrared ray wireless signal is disposed on the remote controller 1, and the reception of the wireless signal is notified by alarm sound and the like.