an opposite base plate and top and bottom cover boards respectively attached to upper and lower edges of the side panels to secure the front panel and the base plate in the channels of the side panels such a structure enhances simplification of assembling disassembling the water heater enclosure and provides flexibility in modification of overall outside appearance of the water heater by replacing the side panels and the front panel to thereby eliminate troubles and inconveniences that are encountered in the conventional water heater enclosures application_number US 29323805 A description the following descriptions are of exemplary embodiments only and are not intended to limit the scope applicability or configuration of the invention in any way rather the following description provides a convenient illustration for implementing exemplary embodiments of the invention various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims with reference to the drawings and in particular to fig1 and 2 an enclosure of water heater constructed in accordance with a first embodiment of the present invention comprises two opposite side panels 10 which are substantially rectangular having front and rear edges each side panel 10 comprise a first front channel 11 preferably aluminum extruded longitudinally extending along and integrally formed at the front edge thereof and a second rear channel 12 also preferably aluminum extruded longitudinally extending along and integrally formed at the rear edge thereof the first and second channels 11 12 are opposite to each other a rib 13 preferably aluminum extruded longitudinally extends between and opposite to the first and second channels 11 12 and is integrally formed with each side panel 10 opposite ends of the rib.