TM 10-6640-239-13 5-27 5-14.    HOT WATER HEATER DISTRIBUTION BOX. This task consists of: a.   Remove b.   Install INITIAL SET-UP Tools Required General Mechanics Tool Kit, (Appendix B, Section III, Item 1) Materials/Parts Required Lockwashers, (4) Equipment Conditions Sulfur Apparatus Removed (Paragraph 4-69) Water Bath Removed (Paragraph 4-69) Grease Working Machine Removed (Paragraph 4-69) WARNING ELECTRICAL SHOCK Before performing any  maintenance actions on electrical equipment, ensure  all electrical power has been turned off.  Failure to comply with this warning may result in serious injury or death. REMOVE Remove Hot Water Heater Distribution Box.  See Figure 5-10. a. On Main Power Panel set water heater circuit breaker A1CB17 to OFF. b. Remove shelf from cabinet U to gain access to hot water heater distribution box (1). c. Remove screw (2), latch (3), and open cover (4). d. Tag and disconnect wiring from relay (5). e. Remove two screws (6) and relay (5). f. Remove four screws (7) and panel (8). g. Remove conduit (9) and wiring from hot water heater distribution box (1). h. Open cabinet T to gain access to hardware. i. Remove four screws (10), washers (11), lockwashers (12), nuts (13), and hot water heater distribution box (1). Discard lockwashers.