Abstract: A modular water heater connection apparatus for integrally joining the cold water input and hot water output bungs of two conventional hot water heaters arranged in tandem. Low-profile hot and cold water connection circuitry cooperates to connect two substantially smaller water heaters in parallel to preclude the need for replacing one of the smaller ones with a substantially large and expensive water heating unit. The apparatus includes a structural configuration for isolating the position of the hot water connection circuitry to preclude inadvertent contact therewith.