There are several types of water heaters you can choose from:

 

    storage tank style

   high-efficiency tank style

    tank-less

    combo systems

    indirect

 

Storage tank

These are the most commonly used water heaters. They heat the water with GAS or Electric  and hold 76 to 380 liters (20 to 100 gallons) of hot water – enough for most homes. Today's energy-efficient models feature extra insulation, which reduces heat loss through the tank walls.

Storage tank water heaters heat water in an insulated cylinders that range in size from 114 to 283 liters (30 to 75 gallons) of water – the average Canadian home uses 227 to 277 liters (60 to 73 gallons) of hot water per day.

A typical tank is steel lined with glass. Some high-end models are lined with stainless steel, and are a good choice if you have acidic water or high mineral content.

Benefits are:  instant hot water,   high water pressure lasts longer (depending on tank capacity), life expectancy of 10 to 12 years, run multiple appliances concurrently: shower, do laundry and run the dishwasher all at the same time, standard efficiency.

 

High-efficiency water heaters are up to 40 per cent more efficient than standard efficiency models. These water heaters often have better insulation, heat exchangers and heat traps to reduce heat losses.  They also have features such as electronic ignition, which means you don't need a continuous pilot light.

There are two types of high-efficiency natural gas water heaters:

    Direct-vent, or "sealed combustion," water heaters intake and exhaust from outside the home, rather than inside the room. Exhaust gases are vented to the outside, with the aid of a blower. Efficiency is improved by reducing off-cycle losses. These models are also some of the safest because backdraft (though rare and preventable in other models) is impossible.

    High-efficiency condensing heaters collect condensation to reduce heat loss. Though the extra anti-corrosion materials needed for this system add cost, the high efficiency more than makes up for it.

 

Tankless water heaters

On demand, or tankless, water heaters "fire" only when you need it rather than storing it at constant heat. They can be your home's only source of water heat, or you can add them to your traditional heating system.

Benefits:

    limited flow reduces fuel consumption up to 30 per cent, depending on BTU input and AFUE of equipment,

    no floor space required – great for compact spaces

    energy is saved, as water is not kept constantly heated

    unlimited capacity straight from groundwater

 

Combo or integrated heating systems provide domestic hot water and most types of space heating all from a single hot water tank.

 

Indirect water heaters

This system uses a boiler to heat both your water and living space. While more expensive than average storage tank heaters, they have higher capacity and improved efficiency. They also have an extended lifespan because they are made of stainless steel.

The large capacity is great for large homes and hot tubs, but also for condos as it reduces the number of appliances and saves space.