How Cottage Plumbing Gets Winterized: Every Tap, Toilet, and Pump

Winterizing cottage plumbing is a sequence, not a single chore

If you have ever looked up how to winterize cottage plumbing in Ontario, you have probably found a dozen lists that each leave something out. The truth is simpler than the internet makes it: it is one set sequence, done the same way every time, and the order is the whole point. Each step sets up the next, and skipping one is exactly how water ends up sitting somewhere it can freeze.

Water is behind most of the serious winter damage we get called about on the Bruce and the Lake Huron and Georgian Bay shore. A pipe, tank, trap, or fixture with water still in it can freeze, expand, and split — and a split line can flood a cottage the moment things thaw, often weeks before anyone is back to see it. That is why we give the plumbing more care than any other part of a closing.

Here is the full sequence we walk on every closing, in order, with the reason each step exists.

Step 1: Shut the water off at the source

Everything starts by cutting the supply, so no new water can push into the lines while you empty them.

• We shut the water off at its source and switch the pump off at the breaker, so it cannot try to re-pressurize a system that is being opened up.
• On a municipal hookup, that means closing the main valve or the curb stop out at the lot line.

With the supply off, the system is closed and ready to drain. What “the source” actually is depends on how your cottage gets its water — and that changes this first step more than any other.

Where your water comes from changes step one

Three setups are common around here, and being honest about which one you have matters.

• Drilled or dug well: A pump pulls from the well, and a pressure tank inside the cottage holds the working supply. The water down in the well sits below the frost line and looks after itself; it is the pump, the pressure tank, and the lines inside the building that have to be drained.
• Lake intake: Many older shoreline cottages draw straight from the lake through an intake line and a foot valve, with a jet pump and pressure tank inside. Here the intake line itself has to be drained back toward the lake, or the foot valve pulled, on top of emptying the pump and tank.
• Municipal water: Some serviced communities have a curb stop at the property line. Shut it there, then drain the house side down the same as any other system.

The source changes how you shut off and which extra lines need attention. From here on, though, the rest of the sequence is the same for all three.

Step 2: Open every tap and the low drains

Now you let gravity and air pull the water out.

• We open every tap, hot and cold, on every level — upstairs, down, and the utility sink — so air can get in behind the water.
• We open the low drain points, the valves a plumber puts at the bottom of the lines for exactly this.
• The outdoor taps and hose bibs come next, since they sit closest to the cold and get forgotten first.

Opening the high taps and the low drains at the same time is what lets a line actually empty instead of holding a vacuum. Miss a tap on the far side of the cottage and that whole branch can stay full.

Step 3: Drain the pressure tank and the water heater

These two hold the most water in the entire system, and they are the two most often left full.

The pressure tank empties through its own drain once the pump is off and a tap is open. The water heater is the one that bites people.

• We cut the power to an electric tank first — an electric element left switched on in a tank with no water in it can burn itself out in seconds.
• On a propane unit, we set it to pilot or off.
• Then a hose goes on the drain valve, and the tank empties fully.

Why this earns its own step: a water heater holds tens of litres, tucked in a closet or the basement, out of sight while you work through the fixtures you can see. Left full in an unheated cottage, that water can freeze, expand, and crack the tank shell or split its fittings and valves. When it thaws, the leak is right at the heart of the water system. It is the single most common miss we write up in the cottage-closing mistakes we see every spring.

Step 4: Blow the lines out, or gravity-drain to the low point

Opening the taps gets most of the water. It does not get the water trapped in low spots, long horizontal runs, and under-floor lines that do not slope toward a drain.

• We blow the lines out with compressed air at a controlled pressure, working tap by tap until only air comes through.
• Where a system is plumbed to drain by gravity, we drain it to its lowest point and confirm nothing upstream is still holding.

A single low spot left with water in it is all it takes. Blowing the lines is the difference between “mostly drained” and actually empty, and it is the step most weekend closings skip, because it needs a compressor and a feel for how the system runs.

Step 5: Clear the toilets — tanks and bowls

A toilet holds water in more than one place, and each one has to be dealt with.

• We shut the toilet’s own supply, flush to empty the tank, then sponge out what the flush leaves behind.
• We empty the bowl down as far as it will go.
• The bowl trap gets antifreeze in the next step — it is built to hold water and will not drain dry on its own.

Water left in a tank can freeze and crack the porcelain; water left in the bowl can do the same. Neither is a quick or cheap fix in the spring.

Step 6: Antifreeze in every trap

Every drain in the cottage has a trap — a U-bend that holds a little water on purpose, to block sewer gas from drifting up the pipe. That standing water is exactly what freezes, so every trap gets treated.

• We pour non-toxic plumbing antifreeze into every sink, tub, and shower drain, every floor drain, the washing-machine standpipe, and the dishwasher.
• The toilet bowls get it too, so the trap under each one is treated the same as the rest.

One safety note worth repeating: this is the pink plumbing and RV antifreeze, which is labelled non-toxic — not the bright automotive kind, which is toxic and never belongs in a drinking-water system. The antifreeze does two jobs at once. It resists freezing, and because it does not evaporate the way water does, it holds the trap’s water seal — so a trap that would otherwise dry out over a long winter is less likely to let sewer smell drift into a closed-up cottage. Traps and toilets are the most-skipped part of a rushed closing, which is why treating every one of them is a standard, logged step in our plumbing winterization work.

The lines that get missed

A few water lines live off to the side of the main run, and those are the ones a rushed closing tends to leave full.

• Water treatment gear: A softener, a sediment filter, and any water-treatment canisters all hold water in housings that are often thin plastic. We drain and open the housings so nothing is left inside to freeze and split them.
• Appliance feeds: The fridge and ice-maker line, the dishwasher feed, and an instant-hot tap are all small-diameter lines, and small lines freeze first. Each one gets shut, drained, or treated.
• The extras: An outdoor shower, a wet bar, a second-bathroom branch, or a bunkie on its own line all count. If it carries water, it goes on the list.

None of these hold much water on their own, but a cracked filter housing or a split ice-maker line leaks just as surely as a main. This is where a written system map earns its keep — you drain against a list, not against memory.

Step 7: Label, log, and photograph

The last step is the one that saves you next spring, and it is pure paperwork.

• We label the shut-off valves and tag the water heater and pump, so reopening the cottage months from now is obvious rather than a guessing game.
• We log every step — what was drained, what was blown out, which traps were treated — so none of it lives only in someone’s memory.
• We take photos of the finished work and send them to you, so you can see the closing was done and keep a record of exactly how the system was left.

A written log is what turns “I think we got everything” into a checklist you can actually reopen against in the spring. It is also how a missed line gets caught: if it is not on the log, it did not happen.

This is exactly what our closing does — every step, logged

If that sequence sounds like more than a weekend job, that is because the plumbing usually is. It is the part of a closing where one missed low spot or one forgotten tank costs the most, and the part we get called about after the fact every spring.

We close cottages for a living, from Sauble Beach and the shore through Southampton and Port Elgin around Saugeen Shores, down past Kincardine and Goderich to Grand Bend, and around Georgian Bay through Collingwood. Our plumbing winterization walks every step above — supply off, tanks and heater drained, lines blown out, toilets cleared, and every trap treated — with each one logged and photos sent to you. If you want the whole picture of closing day, our full winterization checklist covers the heat, moisture, wildlife, and security steps that go around the plumbing.

If you would rather talk it through, call us at 519-783-1575 — the phone is answered 7 days a week. Tell us where your cottage is and how its water is set up, and we will walk you through a clear quote up front.