How to Winterize a Cottage: A Muskoka Closing Checklist

Closing the cottage for winter is a Muskoka tradition, and doing it right prevents the frozen pipes, burst fittings, and water damage that can ruin spring opening. Whether you're shutting down completely or keeping some heat on, here's how to winterize your cottage.

Step 1: Decide Heated or Unheated

• Fully closed (unheated): drain all water lines, the water heater, and fixtures, and add non-toxic plumbing antifreeze to traps
• Minimum heat: keep the cottage at a safe low temperature with reliable heat and monitoring. Some owners still drain plumbing as a precaution.

Step 2: Turn Off the Water and Drain the Plumbing Lines

1. Shut off the water supply at the pump or main
2. Turn off and drain the pressure tank
3. Open all taps, hot and cold, starting at the highest fixtures
4. Drain the water lines at the lowest drain points, and blow out lines with compressed air if needed
5. Drain the lake intake line if it's exposed to freezing
6. Flush toilets and remove as much water as possible from the tanks and bowls
7. Pour RV/plumbing antifreeze into traps, toilets, and drains (never automotive antifreeze)

Step 3: Winterize the Water Heater

• Turn off power or gas to the water heater
• Drain the tank completely via the drain valve
• Leave the drain valve open or follow the manufacturer's instructions
• For tankless water heaters, follow the drain-down procedure to protect the heat exchanger

Step 4: Water Treatment, Filters, and Softeners

Drain or remove water filters, UV systems, and softeners that could freeze, following the manufacturer's steps.

Step 5: Septic Tank Considerations

Don't add antifreeze in large quantities to the septic system. Check the tank and pump well before closing if it's due.

Step 6: Heating and HVAC

• Heated cottages: book a fall furnace or heat pump service, install a Wi-Fi thermostat with temperature alerts, and make sure backup heat works
• Unheated cottages: shut off and secure fuel-burning appliances, turn off gas or propane supply valves as appropriate, and protect outdoor units from snow and ice
• Clear vents and intake/exhaust pipes
• Test smoke and CO alarms

See HVAC Maintenance Plans and Heat Pumps for Cottages.

Step 7: Protect Against Snow Load and Weather

• Clear gutters and check the roof
• Know your roof's snow load limits and arrange snow removal if needed
• Trim overhanging branches
• Secure docks, boats, and outdoor furniture

Step 8: Talk to Your Insurance Company

Many cottage insurance policies have conditions for unoccupied or winterized properties, such as required inspections, heat, or draining. Check with your insurer or broker before closing to stay covered.

How Much Does It Cost to Winterize a Cottage?

DIY winterizing costs little beyond antifreeze and time. Professional plumbing and HVAC winterizing costs vary with the size of the system and access.

How to Turn a 3-Season Cottage Into a 4-Season Cottage

If you'd rather use the cottage all year, a year-round conversion with a proper heating system, insulated plumbing, and ventilation is the long-term solution. See Cottage Year-Round HVAC Conversions.

How to Winterize an Unheated House

The same principles apply: drain all water, protect traps with antifreeze, shut off water heaters, and secure fuel appliances.

Book Your Free Quote

Call (705) 706-7622 or request a free quote online. Our team will get back to you quickly to book a visit.