In North America, most homes are heated with furnaces or hydronic boiler systems. The ratio of annual heat output compared to annual energy consumed by your furnace or boiler is called AFUE, used to determine its efficiency. Over the past 20 years, higher-efficiency boilers have taken over the market, and residential gas boilers sold in Canada must have an AFUE rating of 82% or higher, but condensing boilers blow them out of the (hot) water at a whopping 90% or higher, making them “the boiler of the future.”


High Efficiency Boilers

  • Fueled by gas or oil
  • Use waste heat to preheat cold water that enters the boiler
  • Condenses water vapour to liquid water
  • Increases efficiency by 10-12%
  • Typically have a 90-98.5% AFUE ratio
  • Require a drainpipe for the condensation produced during operation
  • Can be more expensive short-term, but can help save you money in the long run


Conventional Boilers

  • Burn fuel that produce gases (including steam) that pass through a heat exchanger to transfer heat to water and raise the temperature
  • Typically have a 56-70% AFUE ratio for lower efficiency systems, and 80-83% ratio for mid-range efficiency hydronic systems
  • Have a natural draft that creates a flow of combustion gases but can be outfitted with an exhaust fan to control the flow better
  • Might have a continuous pilot light or an electronic ignition
  • Heavy heat exchanger


Older models can be retrofitted to comply with the new regulations, increase their efficiency, and save you money, something that a Red Deer Plumb-Pro journeyman plumber can help with!

In Western Canada, energy suppliers sometimes offer energy rebates when these high efficiency modulating condensing boiler systems are installed, so replacing your conventional boiler (or furnace) is also an option. Red Deer Plumb-Pro’s installation professionals specialize in maintenance and installation of high efficiency modulating condensing boilers, so if your hydronic boiler system is not performing up to speed, give us a call today!