Electric water heaters operate by passing current through electrical resistance heating elements. Each unit usually has two of these elements – one in the middle of the tank and one at the bottom. A thermostat that senses the water temperature triggers the elements. When the temperature drops below a certain threshold, the current is sent and heats the water until the high temperature threshold is met.
Fuel fired water heaters have a burner rather than electrical elements. The burner is supplied with gas through a control valve that has a thermostat switch. For most units, the burner is underneath the tank. The exhaust is vented through the center of the tank or around the sides. There is more wear and tear on fuel-fired tanks than electric units because the flame to heat the water heats the tank. These units often have a shorter life span than electric models.
These units have something called a recovery rate. This is the speed at which the unit heats water. It’s referred to as recovery because once the water is being drawn faster than it is being heated, the temperature drops and has to be recovered. Choosing a water heater that has an appropriate capacity and recovery rate depends on how much water your household needs and how your unit heats the water.
Typically heaters with low recovery rates have a high tank capacity. Although it takes longer to heat the water, there’s more of it for intermittent use. Units with a high recovery rate usually have a smaller tank because the water is heated faster. Generally speaking, electric models have lower recovery rates than fuel run units.
Tankless water heaters are becoming more popular in many Canadian homes. These units heat water at the tap as you use it. A coil of pipe connects the cold water supply to your hot water delivery pipes. Because tankless heaters only heat water as it’s used, there’s no cost for maintaining heat in a large volume of water during periods of low usage.
These are efficient and convenient systems but they are not without their drawbacks. They produce water that is much hotter than is usually necessary so installing a cold water mixing valve is a good idea to prevent scalding. They also have a limited capacity and need to be situated near the tap they are serving. If you have a large house, you will likely need more than one unit to heat water at all your taps.
Mckinnon Heating and Cooling services all water heater types. If you are in need of maintenance or looking to install a new unit, give us a call. We are located in Markham, Ontario and serve all surrounding areas.