FAQ'S - Water Heaters
The relative energy efficiency of these systems depends a lot on other factors such as the amount of heat loss from a more traditional storage tank system or the length of time hot water is stored before it is used. In practice they require a good deal more energy per volume of heated water than conventional systems. The traditional storage tank type of water heater can be quite efficient if the tank and the hot water pipes are properly insulated.
The on-demand type heaters have their uses in the appropriate situation. We have found them practical and efficient in situations where hot water is used only occasionally such as in some shop situations or where a fixture is at a considerable distance from a traditional storage tank water heater, such as in a guest house or pool house. They can also be handy if you are adding hot water to a structure that has been cold-water-only and the cost or inconvenience of adding a complete hot water piping system will be prohibitive.
They do require much more maintenance than traditional water heater.
We don’t recommend draining them for any reason unless prior to replacing them. The way scale forms in Calgary you won’t get anything substantive out. Having a softener is a good idea to keep the tank clean and free of scale but also to keep metal bare. However, this, and a few other reasons will reduce the life of the tank by approximately one third.