Your Cottage's First Winter Under Ontario's New CO Alarm Rule
Every cottage owner knows the sound. It's 2 a.m., it's your one weekend up north, and somewhere in the cottage a small plastic disc goes chirp. You lie there doing math: smoke alarm or CO alarm? Battery or end-of-life? Which storey? Do we even own a ladder?
This winter there's one more question worth asking: does your cottage meet Ontario's updated carbon monoxide alarm rule? Changes to the Ontario Fire Code took effect on January 1, 2026, so this is the first full heating season under them. Here's what changed, in plain language, with links to the official sources.
What changed on January 1, 2026
According to the Province's carbon monoxide safety page (updated December 30, 2025), a CO alarm must be installed in a house that:
has a fuel-burning appliance (think furnace, wood or gas fireplace, wood stove, water heater, propane appliances)
has a fireplace
has an attached garage
is heated by air from a fuel-burning appliance that is not contained within the home (new as of January 1, 2026)
And the alarms must be installed:
adjacent to each sleeping area, meaning the hallway or area outside the bedrooms
on every storey of the home, including storeys that do not have sleeping areas (new as of January 1, 2026)
That second point is the one that catches cottages. A walkout basement with a games room, a main floor with no bedrooms, a loft: each storey now needs a CO alarm if the rule applies to the house. The Office of the Fire Marshal's communique on the amendment (O. Reg. 87/25, approved June 2, 2025) confirms the changes came into force on January 1, 2026, with a few exceptions.
Who is responsible at a rental cottage?
The Province says building owners are responsible for complying with CO alarm requirements under the Fire Code. In rental suites, landlords must install and maintain alarms, test them annually and at other set times (such as when the battery is replaced or a tenancy changes), and give tenants a copy of the maintenance instructions.
A short-term rental isn't the same as a long-term tenancy, but the practical answer for a cottage owner is the same: it's your cottage, so it's on you. If you're not sure how the rule applies to your property, the Province says to contact your local fire department.
The Province is also clear that it is against the law for anyone to remove the batteries from, or tamper with, a CO alarm. That's worth putting in your house rules.
Your cottage CO walk-through for this winter
List every fuel-burning thing. Furnace, wood stove, fireplace, propane heater, gas range, water heater, generator, and the attached garage if you have one.
Count your storeys. Basement, main floor, second floor, loft. Each one needs an alarm if the rule applies.
Find every sleeping area. Put an alarm in the hallway or area outside each one.
Check the labels. Look for the logo of a recognized testing agency such as CSA, ULC or ETL. Hardwired, battery-operated and plug-in alarms are all permitted, and combined smoke and CO units are common.
Test, then write it down. The Province says to test CO alarms every month, replace batteries every year and replace alarms according to the manufacturer's instructions. Keep a simple log at the cottage.
Book the inspection. Have fuel-burning appliances, chimneys and vents cleaned and inspected by professionals every year before cold weather sets in.
Ask about outbuildings. If a bunkie or guest cabin has a fuel-burning appliance or fireplace, ask your local fire department how the rule applies to it.
Tell your guests what they need to know
A CO alarm sounds different from a smoke alarm. The Province says everyone in the home should know the difference.
If a CO alarm sounds, get everyone out immediately and call 911 from outside.
Barbecues and portable generators are outdoor-only, away from doors, windows and vents. Never in the garage, even with the door open.
Open the flue before lighting the fireplace.
Keep outside vents and chimneys clear of snow.
About that 2 a.m. chirp
A chirping CO alarm usually means a low battery or that the alarm has reached its end of life. The Province suggests checking the manufacturer's instructions so you know the difference between the low-battery warning, the end-of-life warning and an emergency alarm. Leave spare batteries and a step stool at the cottage, and put the instructions in your guest guide so nobody has to guess.
Not sure your cottage is ready for winter guests? Call 705-996-6769 and we'll walk through it with you.
Mark your calendar: CO Awareness Week, November 1 to 7
Ontario's Hawkins Gignac Act proclaims the week beginning November 1 as Carbon Monoxide Awareness Week. It lines up with the end of daylight saving time on November 1 this year, which makes it an easy reminder: change the clocks, test the alarms.
This post is general information, not legal advice. For questions about your specific property, contact your local fire department.
Carbon monoxide alarm requirements in Ontario: quick answers
Does my cottage need a carbon monoxide alarm?
If it has a fuel-burning appliance, a fireplace or an attached garage, or is heated by air from a fuel-burning appliance outside the home, yes, under the Ontario Fire Code.
Where do CO alarms need to go?
Adjacent to each sleeping area and, since January 1, 2026, on every storey of the home, including storeys without bedrooms.
How often should I test a CO alarm?
The Province says to test every month, replace batteries every year and replace the alarm according to the manufacturer's instructions.
