Closing the Cottage Before Thanksgiving: A Muskoka Plumbing Winterizing Walkthrough

Closing the Cottage This Thanksgiving? Start With the Water.

For a lot of Muskoka families, Thanksgiving weekend means one last turkey dinner at the lake... and then closing the cottage.

This year, Thanksgiving Monday falls on October 12, 2026, and by then cold nights are already routine around Muskoka.

That matters, because water left in a pipe, pump, toilet or water heater can freeze, expand and crack whatever it's sitting in.

The worst part? You usually don't find the damage until May, when the water goes back on and starts coming out somewhere it shouldn't.

The good news? Winterizing cottage plumbing isn't complicated. It's a sequence. Do the steps in order and don't skip any.

Let's break it down.

💡 Important: Every cottage is plumbed a little differently. Use this as a general guide, follow the manufacturer's instructions for your pump and water heater, and if you're not sure how your system is put together, call a licensed plumber.

🧰 What You'll Need

• Plumbing/RV antifreeze (the pink, non-toxic propylene glycol kind)
• Garden hose for draining the water heater and pressure tank
• Air compressor and a blow-out adapter (if you're blowing out the lines)
• Buckets, a sponge and a wet/dry shop vac
• Wrenches, pliers and a flashlight or headlamp
• Tags or tape and a marker for labelling valves and breakers

👉 Never use automotive antifreeze (ethylene glycol) or windshield washer fluid. Automotive antifreeze is toxic, and it doesn't belong in a system you'll drink from again, or in a septic system that drains toward the lake. Use plumbing antifreeze straight from the jug, without diluting it.

Step-by-Step: Winterizing Your Cottage Plumbing

Step 1: Turn Off the Power

• Switch off the water pump at its breaker (#1 in the pump diagram in Step 4).
• Switch off the electric water heater at its breaker. For a propane or gas heater, turn the gas control off and close the gas valve to the heater.

⚠️ Safety first: Never drain an electric water heater with the power on. An element that comes on in an empty tank can burn out very quickly. Label that breaker so nobody flips it back on before the tank is refilled in the spring.

Step 2: Shut Off the Water at the Source

Close the main shut-off valve (#4 in the diagram) near the pump (lake intake), after the pressure tank (well), or at the main or curb stop (municipal service).

No main shut-off, or is the old one seized? Put a new ball valve on your spring to-do list.

Step 3: Open Every Tap

• Open every tap, hot and cold, on every level.
• Don't forget the bunkie, boathouse, sauna or outdoor shower if they're on the same system.
• Open any low-point drain valves.
• Leave everything open for the winter.

Miss one tap on the far side of the cottage and that whole branch can stay full.

Step 4: Drain the Pump and Pressure Tank

Here's where most of the water hides. Use the diagram below to find each part on your own setup. 

Jet pump: most lake-intake and shallow-well cottages use one. Remove the priming plug on top (#2) and the drain plug near the bottom of the pump housing (#3), and let it drain into a bucket.

👉 Put the plugs in a zip-top bag and tape it to the pump. You'll thank yourself in May.

Pressure tank: hook a hose to the drain valve at the base of the tank (#5), run it to a floor drain or outside, and let it empty completely.

💡 Every pump is a little different. The diagram shows a typical setup, so check your pump's manual for the exact plug locations.

Submersible well pump: the pump sits below the frost line, so the job is draining everything above ground. If you're unsure which parts hold water, ask your well installer.

Step 5: Drain the Water Heater

1. Double-check the power (or gas) is off. If you can, shut it off a few hours ahead so the water cools. It can be very hot.
2. Open a hot water tap so air can get in.
3. Run a hose from the drain valve to a floor drain or outside, away from the septic bed.
4. Open the valve and let the tank empty completely.

Step 6: Blow Out the Lines

Opening taps gets most of the water out, but not what's sitting in low spots and long runs under the floor.

1. Connect your compressor with a blow-out adapter.
2. Keep the pressure low and controlled. Older cottage plumbing doesn't like high pressure, so follow your plumber's or pipe manufacturer's guidance.
3. Open one fixture at a time, hot and cold, until only air comes out.
4. Don't forget toilet supply lines, outdoor taps, the outdoor shower and appliance lines.

Drain filter and softener housings too, and follow the manufacturer's instructions for UV systems, dishwashers and washing machines.

Step 7: Antifreeze in Every Trap and Toilet

Every drain has a trap, the U-bend that holds water to keep sewer gas out. You can't blow that water out, and it's exactly what freezes.

• Toilets: close the supply, flush, then sponge or vacuum the tank and bowl as dry as you can. Pour antifreeze into the bowl until it fills the trap.
• Drains: pour non-toxic plumbing antifreeze into every sink, tub, shower and floor drain, plus the washing machine standpipe. Check the jug for how much to use.

Step 8: Pull the Lake Intake Line

The intake line and foot valve sit in shallow water, where ice forms first.

1. Pull the line and foot valve out of the lake.
2. Let the line drain back toward the lake, or blow it out.
3. Check the foot valve and screen for damage.
4. Coil and store the line above the spring high-water mark.

👉 Running a heated line for winter visits? Make sure the heat cable is rated for your pipe and installed to the manufacturer's instructions. It's not a substitute for draining a system that won't be used.

Step 9: Outdoor Taps

• Disconnect, drain and store all hoses inside. Even frost-free sillcocks can crack with a hose attached.
• Close the inside shut-off (if there is one), then open the outdoor tap to drain it and leave it open.

Septic System Notes

• Plumbing/RV antifreeze only. Nothing automotive goes down the drain.
• Stake the tank lid, cleanouts and edges of the bed so nobody drives, parks or plows over them.
• Keep vehicles, snowmobiles and ATVs off the bed. Compacted snow reduces the natural insulation.
• Due for pumping? Talk to your septic contractor about timing, especially if you have a high water table.
• Check for running toilets or dripping taps before you leave.

When to Call a Licensed Plumber

Call a pro if:

• Your system is complex (multiple buildings, long buried runs, water treatment or in-floor heat)
• You're not sure how it's plumbed or where the low points are
• It's your first closing at a newly purchased cottage
• Valves are seized or fittings are already leaking

✔ Cottage Closing Checklist

👉 Save or print the checklist above and keep it at the cottage. Here it is in text form too:

✔ Pump and water heater power off
✔ Main water supply closed
✔ All taps and low-point drains open
✔ Pressure tank, pump and water heater drained
✔ Lines blown out at low pressure
✔ Filter housings drained, appliances winterized
✔ Toilets emptied, antifreeze in every bowl and trap
✔ Intake line pulled, drained and stored
✔ Hoses off, outdoor taps open
✔ Septic tank and bed marked
✔ Breakers, valves and pump plugs labelled

💡 Pro Tip: Photograph your valves before you start and again when you're done, and make a spring list of anything that needs fixing (a dripping valve, a seized shut-off, a pipe that needs insulation).

Picking Up Supplies Before the Long Weekend

Look for plumbing/RV antifreeze, foam pipe insulation, heat cable, shut-off and drain valves, outdoor faucet covers, pipe fittings and thread seal tape, plus steel wool and sealant to keep mice out of pipe gaps. Counting on something specific? Give us a call before you head up.

Final Thoughts

Closing the cottage properly takes a little time, but a lot less than dealing with a cracked water heater in the spring.

Shut it off. Drain it. Blow it out. Protect the traps. Write it down.

Have questions about closing up your cottage this fall? Stop by Chamberlain Timber Mart and talk to one of our experienced sales associates. We'll help you find the right supplies and get your cottage ready for winter.

Happy Thanksgiving from all of us at Chamberlain Timber Mart!