Many people in Calgary have been startled by a sudden cold shower one morning because of a failing water heater. These units become less efficient over time due to age or sediment buildup. Other issues include the tank being too small to provide an extra person with hot showers in the house. In that case, you might need to consider upgrading to a larger tank to have more hot water reserves. Or, you can upgrade to a tankless water heater. Calgary homes that face problems involving malfunctioning parts or inefficiency could see significant improvements from a tankless upgrade.