To protect yourself from the risk of electrocution in the bathroom, the electrical standard imposes safety distances when you plan to install electrical appliances such as electric towel warmers. It is therefore strongly advised to refer to it before choosing the location of its radiator.
Choose the location of the radiator
In volume 0: ie in the bathtub or in the shower tray, all equipment and electrical cables are prohibited. On the other hand, very low voltage (12V) luminaires are allowed provided that the transformer is located in zone 3.
In volume 1: ie above the bathtub or the shower tray, all the following electrical elements are prohibited: switches, sockets, switches, lighting and ducted electrical conduits or metal conduit. Electrical connections to sockets in volumes 2 and 3 are nevertheless possible.
In volume 2: That is to say 60 cm around the shower or bath area, There are still many prohibitions: non-flush switches, transformerless sockets, junction boxes, metal sockets, lamps not protected by a ceiling lamp and electrical conduits under sheath or metal conduit.
In volume 3: Space that corresponds to the space between 60 cm and 2.4 meters from the main water zone, outlets without earth contact or without separation transformer are prohibited. It is from this area that it is possible to install useful electrical appliances in a bathroom. It is therefore in this part of your bathroom that it is recommended to install your towel rail.
Of course, remember that all electrical devices must be protected from splashing water.