Planning a winter weekend away—or a longer trip—raises a practical question: how far can you turn down the heat without creating moisture, plumbing or comfort problems? The right answer is usually a moderate setback, not switching the heating system off.
The short answer
For most homes, 17°C is a sensible starting point while you are away. Natural Resources Canada recommends 17°C when a home is unoccupied and generally advises against going lower because cooler building surfaces can increase the risk of moisture accumulating in exterior walls.
That is a general guideline, not a guarantee for every house. The safe setting can be higher if the home has vulnerable plumbing, uneven heating, an older heating system, a crawlspace, a history of frozen pipes or rooms that become much colder than the thermostat location.
Do not turn the heating system off
An empty house still needs heat. Outdoor temperatures around Schomberg can fall quickly, and shutting the system off removes the protection that warm indoor air provides to plumbing, finishes and equipment.
Use the thermostat’s normal heat mode and an “away,” “hold” or scheduled setback. Do not shut off power or fuel to the furnace, boiler or heat pump, and do not open equipment panels or adjust wiring, gas valves, fan speeds or internal controls.
Why 8°C is not a whole-house thermostat target
King Township advises keeping areas that contain indoor water pipes above 8°C, especially near the water meter. That is a minimum temperature around plumbing, not a recommended thermostat setting for the entire home.
The thermostat may be in a warmer central hallway while pipes run through colder exterior walls, cabinets, basements or crawlspaces. A 17°C thermostat setting provides a more practical buffer, but homes with known cold spots may need a higher setting or plumbing advice.
Your heating system may change the best setback
- Forced-air furnace: a moderate setback is usually straightforward, provided supply registers and return grilles remain open and unobstructed.
- Heat pump: follow the thermostat and equipment manual. A large temperature recovery can bring on auxiliary heat, so a modest, steady setback may be more suitable. Our guide to AUX HEAT explains what that thermostat message means.
- Boiler or radiant system: these systems can respond slowly. Natural Resources Canada notes that some hydronic systems are not well suited to aggressive setbacks.
- HRV or ERV: do not automatically shut ventilation off. Use the settings recommended for the installed system and indoor humidity. See our guide on running an HRV in winter.
A safe before-you-leave checklist
- Test the heat before departure. Raise the setting briefly and confirm that the system starts and warm air or heat reaches the living areas. Return the thermostat to the away setting afterward.
- Choose a moderate hold temperature. Start at 17°C unless the equipment manual, plumbing layout or past experience calls for a higher setting.
- Keep airflow paths open. Do not close heating registers or block return grilles with luggage, furniture or stored items.
- Check the filter only as the manual directs. If an accessible filter is visibly loaded or due for replacement, use the correct size and type. Do not open electrical or burner compartments.
- Review humidity and ventilation. A very humid house can develop condensation as indoor temperatures fall. Use normal homeowner controls and avoid disabling the HRV or ERV without checking its manual.
- Use alerts wisely. A connected thermostat or low-temperature sensor can warn of a problem, but it does not repair the heating system. Arrange for a trusted person to have access and review any requirements in your home-insurance policy.
- Consider water protection separately. King Township tells residents leaving for an extended period to contact ServiceKING about having the water shut off to reduce freezing risk. This does not replace keeping the home heated.
When to arrange heating service before a trip
Book an assessment if the heating system is short-cycling, making new noises, producing weak airflow, failing to reach the thermostat setting or leaving one area much colder than the rest of the house. A warning light, repeated system lockout or an unresponsive thermostat also merits professional attention.
If you smell gas, hear a carbon-monoxide alarm or see smoke, leave the building and contact emergency services or the appropriate utility from a safe location. Do not try to diagnose or restart fuel-burning or electrical equipment yourself.
For help checking a heating problem before you leave, review our heating service options and call Schomberg Heating & Cooling at (905) 939-2350. For time-sensitive service, call rather than relying on the website form.