David in Unionvill

I just got a JSW 50G hot water tank and Trane XV-95 furnace installed by Buttons. They didn't insatll anti_scald valve for my hot water tank. This mixing valve is for limit hot water temperature to not more than 49 degreeC. I have confirmed with Ontario Building Code that it is code to install it when replace a hot water tank.Buttons said it is NOT include in the price. How can they gave a quote without follow the code? The quote I got from Home Depot is $1420, which include a new tank, a mixing valve and all installation. With the same price, Buttons just include a new tank and installation. They charge another $250 for a mixing valve. I think they are over-priceing.