Cottage opening checklist: the spring start-up, in order

Before you unlock the door

Start outside, and take your time. Walk the whole building before you go in, looking for anything the winter did: shingles on the ground, a sagging eavestrough, a branch through a window, a door that has been forced, tracks or holes where an animal has got under the deck. Look at the foundation and the crawl-space vents, and at the ground where the water lines enter the building. Take photos as you go; if something turns into an insurance claim, pictures from before anything was touched are the most useful ones you will have.

If you smell propane or natural gas at the door, do not go in and do not switch anything on or off. Move well away and call your fuel supplier, or 911 if the smell is strong.

Air it out and look for mice

Once inside, open the windows before anything else. A cottage closed since fall holds stale air, and you want a few minutes of cross-breeze before you start working.

Mice are the usual winter tenants. The Public Health Agency of Canada’s guidance on hantavirus is specific about cleaning up after them: do not sweep or vacuum droppings, which puts particles into the air; wear rubber or plastic gloves, and a respirator in a confined space; spray the droppings and nesting material with a Health Canada-approved disinfectant or one part bleach to nine parts water; let it soak for ten minutes; then wipe it up wet and double-bag it. It is slower than a broom, and it is the right way.

Power next

Turn the main breaker on, then the individual circuits, and listen for anything that sounds wrong. Leave the water heater’s breaker off for now; it comes last. Plug in the fridge and the freezer so they can come down to temperature while you work through the rest of the list.

Then the water, slowly

The water system is the part of an opening that punishes rushing.

1. Close everything you opened last fall. Every drain valve, every tap left open, the drain on the pressure tank and the drain on the water heater. Put back any plugs and caps you removed.
2. Bring the source back. Reconnect or lower a lake intake if yours comes out for winter, and prime a jet pump if it has lost its prime.
3. Open the supply and start the pump. Watch the pressure gauge climb, and listen for running water where there should be none.
4. Bleed the lines one tap at a time. Open each tap slowly until the air stops spitting and the water runs clear, starting nearest the pump and working out.
5. Check every joint and fitting you can see, and the floor under them, before you call the system done.

If a pipe split over the winter you will find out at step three, which is why you stand by the pump while the pressure comes up rather than leaving it to run.

The water heater comes last

An electric water heater must be completely full before its power goes back on: switch it on with air in the tank and the elements can burn out. Open a hot tap and wait until water, not air, comes out of it; then turn the breaker on. A gas or propane water heater is a fuel-burning appliance, and relighting or servicing one belongs with a registered contractor (see below).

Flush the antifreeze

The plumbing antifreeze poured into traps and toilets last fall has to go. Flush each toilet a few times and run every sink, tub and shower until the water is clear. Put the cottage’s appliances that use water, such as the dishwasher and washing machine, through a short empty cycle.

Test the water you drink

If your drinking water comes from a well or a lake intake with treatment, test it at opening. Public Health Ontario tests private drinking water for coliform bacteria and E. coli; it does not test for chemicals. Sample kits come from its laboratories, from the local public health unit or from a pickup location nearby. Its advice is that well water quality can change, so test often. If your system has a filter or UV unit, service it before you trust the result.

Alarms: the legal part

The province is plain about this: it is the law for every Ontario home, cottage, cabin and seasonal home to have a working smoke alarm on every storey and outside all sleeping areas. Test each one with its button and replace batteries as needed; the province recommends testing monthly and replacing batteries at least once a year.

Carbon monoxide alarms are required too if the cottage has a fuel-burning appliance, a fireplace or an attached garage. Since 1 January 2026 Ontario’s Fire Code requires them on every storey, not only next to the sleeping areas. A propane stove, a wood stove or an oil furnace all count.

Fuel-burning appliances

Propane, natural gas and oil appliances are work for a contractor registered with the Technical Standards and Safety Authority, which encourages owners to have fuel-burning equipment inspected every year and leaves it to the owner to ask for the inspection. The province’s carbon monoxide guidance asks for fuel-burning appliances, chimneys and vents to be cleaned and inspected every year before cold weather sets in. If yours were not done last fall, have them looked at before anyone relies on them this season, and book this year’s inspection while you think of it.

Outside, once the water is on

Walk the dock, the deck, the stairs to the water and every railing. Look for boards lifted or split by ice, fasteners that have backed out, cribs or posts that have shifted, and ladders that wobble. Check the eavestroughs and downspouts from the ground and look for trees that leaned over the winter toward the roof or the power line. Anything that needs a ladder, a chainsaw or a licence goes on a list for the right person rather than into the weekend.

The order, in one table

Keep a record

Write down what you found and what you fixed, with the photos, and keep it with last fall’s closing notes. Brokers suggest keeping photos of shut-off valves, thermostat settings and closing checklists; an opening record is the other half of the same file, and it tells you next year what to look at first.