Landlord Heating Requirements in Ontario: Minimum Temperature Rules by City
Ontario sets a 20°C provincial floor (Sept 1–June 15), and most cities require more on top — Toronto 21°C. If you don't know both, you're guessing. Here's exactly what's required, by city.
Ontario Has a Provincial Heating Floor — Your City Sets the Real Number
Here is the part that trips up almost every landlord. Ontario does have a province-wide minimum: under O. Reg. 516/06, heat is a vital service from September 1 to June 15, and a rental unit must be kept to at least 20°C during that period.
But most landlords are held to a higher municipal standard layered on top. Your city sets its own minimum temperature (Toronto requires 21°C), its own heating-season dates, and its own fines. So you need to know both: the 20°C provincial floor, and your city's bylaw.
What does this mean for you? Don't stop at "the province says 20°C." Look up yourcity's property standards bylaw too. If you own properties in two cities, you may have two different sets of rules on top of the provincial floor.
The Bottom Line
Provincial floor: at least 20°C, September 1 to June 15 (O. Reg. 516/06). On top of that, your municipality usually requires more — Toronto requires 21°C (October 1 to May 15). Know both, and follow whichever is stricter.
Heating Rules by City
Here are the heating requirements for Ontario's major municipalities. If your city isn't listed, contact your local bylaw office or search your city's name plus "property standards bylaw heating."
| City | Min Temp | Heating Season | Bylaw Reference |
|---|---|---|---|
| Ontario (provincial floor) | 20°C | Sept 1 – June 15 | O. Reg. 516/06 (vital service) |
| Toronto | 21°C (70°F) | Oct 1 – May 15 | Municipal Code Ch. 497 |
| Ottawa | 20°C day / 16.67°C night | Year-round | By-law 2010-210 |
| Mississauga | 20°C | Confirm locally | By-law 0110-2018 |
| Hamilton | 21°C (70°F) | Confirm locally | Property Standards Bylaw |
| London | 21°C (70°F) | Confirm locally | Check local bylaw office |
| Kitchener | 21°C (70°F) | Confirm locally | Property Standards Bylaw |
| Windsor | 21°C (70°F) | Confirm locally | Check local bylaw office |
Provincial heat starts September 1
Even where a city's window starts later, the provincial vital-service rule requires heat (at least 20°C) from September 1 to June 15. Toronto's 21°C bylaw window is October 1 to May 15, but you still can't leave a unit cold in September. Figures for cities other than Toronto and Ottawa above are general starting points — confirm the exact number and dates with your municipality.
Who Is Responsible for Heat?
This depends on who controls the heating system and what your lease says.
Landlord Controls the System
If you run a central boiler, a shared furnace, or any heating system that the tenant cannot independently control, you are 100% responsible for maintaining the minimum temperature. This is the case in most apartment buildings.
Tenant Has Their Own Furnace
If the tenant has their own furnace (common in rented houses) and the lease explicitly states the tenant pays for gas and controls the heating, then the tenant manages their own heat. But the furnace itself still has to work. If it breaks, you fix it.
The Lease Is Silent
If your lease doesn't say anything about who provides heat, you're on the hook. Silence defaults to the landlord. Don't assume the tenant knows they're responsible unless it's written down.
Even when the tenant pays for gas, you're still responsible for maintaining the equipment. A broken furnace is a maintenance issue under the RTA. The tenant can file a T6 if you don't fix it.
When Can You Turn Off the Heat?
Only after the heating season ends. Period.
The safest answer is mid-June: the provincial vital-service rule keeps heat mandatory through June 15. Toronto's 21°C bylaw window ends May 15, and Ottawa requires adequate heat year-round. Until your applicable date arrives, the heating system must stay operational and capable of maintaining the minimum temperature.
Here's where landlords get into trouble: it's April 20, it's 25°C outside, and they shut the boiler down to save on gas. Then a cold snap hits three days later and the building drops to 16°C overnight. Now you've got a bylaw violation and angry tenants calling 311.
The bylaw doesn't care about the weather forecast. It cares about the calendar. If it's still heating season, the heat stays available. You don't have to run it at full blast on a warm day, but the system has to be ready to fire up the moment temperatures drop.
Don't Gamble on the Weather
A warm week in March doesn't mean heating season is over. If you shut down the system and a cold snap follows, you're in violation. Keep the system available until the official end date.
What Happens If You Don't Comply
You can get hit from two directions at once. That's the part most landlords don't realize.
Municipal Bylaw Enforcement
When a tenant calls 311, a bylaw officer shows up with a thermometer. If your building is below the minimum temperature, you get a work order. You'll have a deadline to fix it. If you don't comply with the work order, fines follow.
In Toronto, fines can reach up to $100,000 for corporations and $50,000 for individuals. Other cities have their own fine schedules, but none of them are cheap.
LTB: The T6 Application
On top of the municipal fine, your tenant can file a T6 maintenance application at the Landlord and Tenant Board. If the Board finds you failed to maintain the rental unit (and inadequate heat counts), they can order a rent abatement. That's money back to the tenant for every day they froze.
So yes, it's possible to get fined by the city and ordered to pay rent abatement by the LTB. Double jeopardy? Not technically, but it sure feels like it.
Enforcement Is Municipal, Not Provincial
Heating complaints go to your local bylaw office, not the LTB. This means faster enforcement and quicker fines. The LTB only gets involved if the tenant separately files a T6 application.
Heating vs Cooling: The Full Picture
Ontario now has temperature rules for both winter and summer. Here's how they compare:
| Heating (Winter) | Cooling (Summer) | |
|---|---|---|
| Source | Provincial floor + municipal bylaws | Municipal (Toronto, Mississauga) |
| Temperature | 20°C provincial / 21°C most cities | 26°C maximum |
| Where | All habitable rooms | Units with existing AC (+ amenity space) |
| Season | Provincial Sept 1–June 15; Toronto Oct 1–May 15 | June 1–Sept 30 (Toronto) |
| Enforcement | Municipal bylaw | Municipal bylaw |
For whether AC is mandatory and the real 26°C city rules, read our Ontario cooling and air-conditioning guide.
Common Mistakes
Using the Wrong Heating Season Dates
Confusing the provincial and municipal windows. Provincial heat is mandatory September 1 to June 15; Toronto requires 21°C October 1 to May 15. Track both, especially the September provincial floor.
Turning Off Heat on a Warm Day
It's 22°C outside in late March, so you kill the boiler. Then it drops to 2°C overnight. Your building is now freezing and you're in breach. The system stays on until the season ends.
Assuming the Tenant Is Responsible
Unless your lease explicitly says the tenant controls and pays for their own heating, you're responsible. A verbal agreement doesn't count. It has to be in the lease.
Skipping Furnace Maintenance
Your furnace dies on January 15 because you haven't serviced it since 2019. Now you're scrambling for an emergency HVAC tech at premium rates while your tenant files a T6. Annual maintenance is cheaper than a repair bill plus rent abatement.
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