Quick answer
Ontario law gives a landlord no fixed number of hours to fix the heat. The Residential Tenancies Act makes heat a vital service a landlord may not withhold (section 21) and makes the landlord responsible for repairs (section 20), so the test is prompt, reasonable action. In winter, that means calling a technician the day the problem is reported and supplying temporary heat until the repair is finished.
How long a landlord has to fix the heat in Ontario is not written down as a number of hours or days anywhere in the Residential Tenancies Act. What the Act sets out is a duty, and the question a bylaw officer or the Landlord and Tenant Board asks is whether the landlord acted promptly and reasonably once they knew. This page is a contractor's summary, not legal advice.
What the Residential Tenancies Act requires when the heat fails
- Section 20: the landlord must keep the unit in a good state of repair, fit for habitation and in line with health, safety and maintenance standards. It applies even if the tenant knew about a problem before moving in.
- Section 21: the landlord must not withhold the reasonable supply of a vital service. Heat is a vital service from September 1 to June 15 under O. Reg. 516/06.
- Section 233: knowingly withholding a vital service is an offence under the Act.
A furnace that breaks down is not the same as a landlord withholding heat. It becomes a breach when the landlord knows and does not act, or lets the unit sit below 20 °C with no interim plan. Waiting three days for a control board in May is reasonable; leaving a family without heat over a January weekend because the office is closed is not.
What a tenant can do if the heat is still out
- Report it in writing straight away. A text or email with the date, the time and the indoor temperature starts the clock on what the landlord knew.
- Call municipal property standards or bylaw enforcement (311 where your city offers it). Officers enforce the local heat bylaw and can issue an order with a compliance deadline.
- Call the Rental Housing Enforcement Unit at 1-888-772-9277. The province's unit handles offences under the Act, such as a landlord shutting off heat.
- Apply to the Landlord and Tenant Board: a T6 application for maintenance problems, or a T2 application about tenant rights where a vital service was withheld. The Board can order repairs and a rent abatement.
Keep paying rent while this runs; withholding it creates a separate problem. Before hiring a technician yourself, read whether a tenant can call their own HVAC company, because the furnace belongs to the landlord. If the house is cooling quickly, how long a house can go without heat in winter explains when pipes are at risk.
What a landlord should do in the first day
- Rule out the simple causes by phone: thermostat batteries and mode, the furnace switch, the breaker, a clogged filter, and snow or ice over the intake and exhaust pipes outside.
- Call a 24/7 emergency repair line the same day. Treat a no-heat call in freezing weather as an emergency, whatever the day of the week.
- Supply temporary heat while parts are on order. Electric heaters on separate circuits will hold a unit for a few days; they are a stopgap, since portable heaters are not allowed as a rental's primary heat source.
- Keep a written record: when the tenant reported it, when you called the contractor, the technician's diagnosis, the part order and the time heat was restored.
That record is what shows reasonable action if a bylaw officer or the Board asks later. A dated invoice from a licensed contractor, with the fault and the repair written on it, does most of the work. Entry is rarely an issue in a no-heat call because the tenant wants the technician in, and the Act allows entry without notice in an emergency or with the tenant's consent.
How long the furnace repair itself usually takes
Most no-heat calls are fixed on the first visit. The usual causes are an igniter, a flame sensor, a pressure switch or a blocked condensate drain, and those common fixes run $150–$450 with the $90–$150 diagnostic credited toward the repair. Typical repair times are covered in how long a furnace repair takes.
Delays come from two places. One is a special-order part, usually a control board or inducer assembly for an older model. The other is a furnace that cannot be put back in service, such as one with a cracked heat exchanger, where the answer is a replacement that takes about a day once the equipment is on site. In both cases temporary heat bridges the gap.
What happens when you call us about a rental with no heat
ZK Mechanical answers its emergency line around the clock and does not add overtime, weekend or holiday surcharges. A TSSA-licensed technician diagnoses the fault, gives the price in writing before any work, and leaves an invoice that states what failed and when it was fixed. The minimum temperatures a unit has to reach are set out in what temperature a landlord must keep a rental.
For emergency heating repair at a rental in Burlington, Oakville, Hamilton, Mississauga, Brampton or west Toronto, call (647) 801-1252 at any hour, or send the details through the contact form if the heat is still partly working.