Why Your Heating Bills Jump Every November

If you open your energy bill in late November or December and wonder what happened, you’re not alone. For many Ontario homeowners, the first full month of cold weather brings a bill that’s noticeably higher than anything they paid all fall.

It isn’t your imagination, and it usually isn’t one single cause. A handful of things stack up at the same time. Here’s what’s behind the jump, and what you can do about it.

1. Your furnace is finally working for a living

From late spring through September, your heating system barely runs. In November, it goes from idle to running for hours a day. Heating is already the biggest energy expense in most Ontario homes, so even a modest change in how long your furnace runs shows up quickly on your bill.

2. The colder it gets outside, the harder your home has to work

Your home loses heat faster as the gap between the indoor and outdoor temperature grows. Keeping a house at 21°C when it’s 10°C outside is much easier than when it’s -5°C. That means your bill rises faster than the temperature drops, which is why the first real cold snap often comes as a surprise.

3. Winter rates and billing changes kick in

Some of the November jump comes from how energy is priced, not just how much you use.

Electricity: Ontario’s regulated electricity prices and Time-of-Use hours are reset every November 1, with winter hours starting that day. This year, the Ontario Energy Board is lowering regulated electricity prices by roughly four to seven per cent, but the Ontario Electricity Rebate is being reduced at the same time, so your overall bill won’t necessarily drop. todocanada

Natural gas: Gas commodity rates aren’t fixed all year either. The Ontario Energy Board reviews natural gas rates every quarter. movingwaldo

The takeaway: even if prices hold steady, you’ll use a lot more energy in November than in October, so the total can still climb.

4. Older or poorly maintained equipment wastes energy

A furnace that’s 15 to 20 years old may be turning far less of the fuel it burns into usable heat than a modern high-efficiency model. A clogged filter, blocked vents or skipped maintenance make it worse, because the system has to run longer to reach the same temperature.

Signs your furnace may be costing you money:

Your bills keep climbing even when your habits haven’t changed

Uneven heating, with some rooms staying cold

Strange noises, frequent cycling or more repairs than before

It’s more than 15 years old

5. Heat is escaping through your home

If your attic is under-insulated or your home is drafty, a lot of the heat your furnace makes is going straight outside. Heat rises, so the attic is often the biggest culprit. Gaps around windows, doors and the basement rim joists add to the problem.

6. Winter habits add up

Shorter days mean more time at home, more lights on, more hot showers and more cooking. None of these is big on its own, but together they push your usage up at exactly the moment your heating load rises.

How to lower your heating bill this winter

Replace your furnace filter. A dirty filter makes your system work harder. Check it monthly during heating season.

Get a furnace tune-up. A professional check can catch small problems before they become expensive ones.

Use your thermostat wisely. A programmable or smart thermostat lets you lower the temperature while you sleep or are away, then warm the house back up before you return.

Seal drafts. Weatherstripping and caulking are inexpensive and make a noticeable difference.

Add attic insulation. It’s one of the most effective upgrades for keeping heat in. Ontario’s Home Renovation Savings Program offers rebates for attic insulation, and it’s currently scheduled to end on November 30, 2026, so it’s worth checking whether you qualify soon.

Ask about equal billing. Many utilities offer plans that spread your yearly costs over 12 even payments, which makes winter spikes easier to plan for.

Consider upgrading an aging furnace. A newer high-efficiency furnace uses less fuel to produce the same heat, and financing options can make the cost manageable.

Frequently asked questions

Why is my heating bill so high in November when it isn’t that cold?

November is when your furnace starts running regularly again after months of little use. Even mild-but-cool weather means many more hours of heating than you used in the summer or early fall.

How much of my energy bill is heating?

In most Ontario homes, heating is the single largest energy use in winter, which is why upgrades to your furnace and insulation can have such a big effect.

Is it worth replacing an old furnace to save money?

If your furnace is 15 or more years old, needs frequent repairs or has uneven heating, a high-efficiency replacement can reduce fuel use and improve comfort. A quote is the best way to know what it would mean for your home.

Need help with your heating?

Whether you’re dealing with a furnace that’s running poorly, thinking about an upgrade or trying to keep heat in your home, the Constant Home Comfort team can help. We’ve been serving GTA homeowners since 2011.

📞 1-855-619-1002

🌐 constanthomecomfort.com

Rebate programs, rates and deadlines mentioned in this article may change. Visit the Ontario Energy Board (oeb.ca) and homerenovationsavings.ca for current information.