Tankless Water Heater Cold Shower . Water heaters of the different brands have different labels. Liquid propane gas (lpg) rate gas pressure: LYEJM 220V 3000W Instant Electric Tankless Cold/Hot Water Heater Shower from www.petagadget.com Tank water heaters store a large amount of hot water, and when it’s not used promptly, the air surrounding the tank can cause it to cool off, wasting your energy. Dial sets temperature between 80 and 140 degrees fahrenheit. Automatic exhaust gas exhaust outlet diameter: