Keeping a Cabin or Seasonal Home From Freezing

Why seasonal property is the high-risk category

An occupied house with a heating failure gets noticed within an hour. Somebody feels the cold, checks the thermostat and makes a call. The failure becomes a service call.

An empty cabin on Island Lake, Lake Nebagamon, Fish Lake or the North Shore has nobody to notice. The furnace fails on a Thursday, the temperature falls through Friday, and pipes in an exterior wall or a crawlspace freeze overnight. When they thaw, they burst, and water runs — sometimes for days — into a building nobody is visiting. That is the difference between a $300 repair and a $40,000 claim.

The building stock makes it worse. Much of the seasonal property around the Twin Ports started as a summer cabin and was winterised in stages by owners doing their best. Plumbing runs through crawlspaces and uninsulated additions. Wall cavities are thin or empty. Heat loads do not track floor area. These buildings are less forgiving than a purpose-built year-round house, not more.

Option one: heat it and monitor it

Set the thermostat to a low but safe holding temperature — typically 50–55°F rather than the 40°F minimum some people use, because the extra margin protects pipes in cold exterior walls and crawlspaces that run well below the room temperature the thermostat sees.

Then monitor it. A remote temperature sensor with cellular or wifi alerting texts you when the indoor temperature drops below a threshold you set. That single device converts a catastrophe into a phone call. If you have a neighbour or caretaker nearby, a low-temperature alert gives them time to get there. For our maintenance customers we can have those alerts come to us as well, so an overnight drop gets a response rather than sitting in a notification nobody saw.

Worth pairing with: a water leak sensor near the mechanical room and any vulnerable plumbing, and an automatic water shutoff valve if the budget allows — that stops the flooding even if nobody reaches the building. Heat tape on the genuinely exposed runs, properly installed and on a working thermostat.

And do the building-side work: insulate accessible plumbing in crawlspaces and rim joists, air-seal where wall cavities connect to cold attics, and leave interior doors open so heat circulates to the rooms with plumbing in them. A cabin heated to 55°F with a closed bathroom door on an exterior wall can still freeze that bathroom.

Option two: drain it down properly

If you are not using the building in winter, draining it eliminates the risk rather than managing it. Done properly that means shutting off and draining the water supply, draining the water heater, blowing out the supply lines with compressed air, draining traps and adding non-toxic antifreeze to them, draining any hydronic system or confirming its glycol concentration, and dealing with toilets, appliances and any exterior spigots.

Done incompletely it gives false confidence — a trapped pocket of water in a low spot will still freeze and split a pipe, and people find that out in April.

The decision between the two is usually about how you use the building. If you want to visit on winter weekends, heat and monitor. If it is genuinely closed from October to May, drain it. What does not work is leaving a building nominally heated with no monitoring and no visits, which is the configuration behind most of the claims we hear about.

One more thing specific to this area: if your cabin is on propane, check the tank level before winter and consider a top-up. A low tank on a −25°F night cannot maintain vapour pressure for a furnace running continuously, and a furnace that cannot get fuel is a heating failure regardless of how good the equipment is.