Water heater

Claim 1

A hot water heater comprising: a housing having a substantially square horizontal cross-section for positioning against an outside wall of a building and including an air inlet adjacent the top rear of the housing, the housing being substantially sealed except for said air inlet; a duct connected to the air inlet to supply air into the housing, the duct being adapted to pass through the outside wall so that air is inspired from outside the building into the housing; a cylindrical hot water tank positioned inside the housing and coupled to the housing, said tank having burner means positioned below the water heater for controllably heating water in the tank; a flue pipe for venting flue gas from said burner, the flue pipe including a portion passing through the duct and spaced from the walls of the duct to carry flue gases outside the building; a vent cap attached to respective outer ends of the flue pipe and the duct and including baffles to deflect outgoing flue gases away from incoming air; and the housing being proportioned so that the walls of the housing have a width substantially equal to the outside diameter of the water tank plus a relatively small clearance to facilitate assembly whereby each of the overall width and depth dimensions of the hot water heater approximates the outside diameter of the water tank and four corner spaces are formed between the upright corners of the housing and the water tank to permit ingoing air to move downwardly from the air inlet to the burner means.