When Should I Turn On My Furnace?
It’s October in Southern Ontario, which means it’s the time of year where there can be large temperature fluctuations hour-to-hour and day-to-day. The comfortable daytime highs and cool nighttime lows prompt homeowners to ask themselves a question we often hear, “When should I turn on my furnace?”
While there is no definitive date to turn your furnace on, there are guidelines you can follow to know when the right time is to turn on your furnace for the cold season.
Turn on your furnace when temperatures dip below 18 degrees
One general guideline to follow when it comes to turning on your furnace, it’s that when the temperature drops below 18 degrees, turn it on.
This recommendation comes from the World Health Organization (WHO). This international body determined that 18 degrees is the ideal indoor temperature for healthy adults. If there are children or elderly people in the home, the WHO recommends turning on the furnace when it falls below 21 degrees.
As you can see in the graph above, showing Toronto’s Hi and Lo temperatures throughout September 2019, we live in a climate that fluctuates between our needing the furnace on and off depending on the time of day.
Regardless of the specific day you choose to turn on your furnace, we recommend that once it’s on, you leave it running on the ‘On’ or ‘Auto’ setting until you shut it down completely in the springtime.
There are many reasons for never shutting down your furnace completely once you’ve turned it on. The reasons are similar to why we recommend you keep your A/C on throughout the summer. We wrote a blog about that topic you can read here.
Before turning on your furnace
If you haven’t yet turned on your furnace, we highly recommend you schedule an HVAC professional to come to your home and perform regular maintenance on your unit.
Not only is this maintenance likely needed to maintain the warranty on your unit, but regular maintenance will also help ensure that your furnace operates efficiently. This keeps your energy costs down — and long-term, bigger maintenance will be kept to a minimum. Yearly furnace maintenance lets us spot small problems before they become big problems.
If you are in need of furnace maintenance or have any questions about your HVAC system, reach out to our team of expertly trained professionals at Therm-All.