plumbers
How to Winterize the Plumbing in a Michigan Cottage or Cabin
Learn the full shutdown sequence for winterizing a Michigan cottage, what plumbers charge, well and pump steps, and the mistakes that lead to claims.
In This Article
How to Winterize the Plumbing in a Michigan Cottage or Cabin
Every April, plumbers from Traverse City to Tawas City get the same phone call. A cottage owner opened the place for the season, turned on the water, and found a split pipe that had been spraying inside a wall since January. The repair bill often lands between $5,000 and $30,000 once drywall, flooring, and mold remediation get added in.
Prevention is cheap by comparison. A full winterization costs less than $400 even when a plumber handles every step, and the window to do it closes fast. Once overnight lows Up North start holding in the 20s, usually by late October, an unheated cottage can freeze solid within a day or two.
Mid-October is the deadline worth circling on the calendar. Every year a stretch of warm fall weather convinces owners they have until Thanksgiving, and every year an early cold snap proves some of them wrong.
Why an Unheated Cottage Freezes So Fast
A year-round home has a furnace cycling and people running water every day. A closed cottage has neither, so the indoor temperature tracks the outdoor temperature within a day or so of the heat going off. When a November night drops to 10 degrees in Gaylord or Grayling, the pipes in an unheated crawl space are close behind.
Water expands about 9 percent when it freezes, and copper, PEX, and fittings all handle that force differently. Copper splits lengthwise, threaded fittings crack, and even flexible PEX can fail at its connections. The break itself is silent, and the damage arrives months later when the ice plug melts and water runs through the split for weeks with nobody there to see it.
The Shutdown Sequence, Step by Step
The job comes down to getting water out of every pipe, fixture, and appliance, then protecting whatever water you cannot remove. Order matters. Draining the water heater before cutting power to an electric unit, for example, risks burning out the heating elements.
Set aside a half day the first time through. Owners who have done it a few seasons usually finish in two to three hours.
- Shut off the water at the source. Close the main valve, or cut power to the well pump at the breaker panel.
- Open every faucet, inside and out, starting with the highest fixture and working down. Leave them all open.
- Drain the system from its low point. Find the lowest drain valve or hose bib on the supply lines and let them empty completely.
- Turn off power or gas to the water heater, let the tank cool, then drain it through a garden hose to a floor drain or outside.
- Flush each toilet until the tank is empty, then pour RV antifreeze into both the tank and the bowl. Use the pink propylene glycol product made for plumbing, never automotive antifreeze.
- Pour a cup of RV antifreeze into every sink, shower, and tub trap, plus any floor drains.
- Drain the washing machine hoses and run a brief spin cycle to clear the pump, then add antifreeze to the drum. Run the dishwasher through its final drain and do the same.
For truly dry lines, blow out the system with an air compressor at 40 to 50 PSI through a fitting near the pressure tank or the laundry hookup. Plumbers do this as standard practice, and it is the difference between mostly drained and empty.
Wells and Pumps at Lake Cottages
Most cottages north of Clare run on a private well, and the pump setup changes the job. A submersible pump down in the casing can stay put all winter because it sits far below the frost line. The pressure tank, the fittings, and the above-ground piping in the crawl space or pump house are the parts at risk.
Drain the pressure tank completely and leave its valve open. An older jet pump mounted above ground needs to be drained through its plug or pulled and stored somewhere warm, since even a few tablespoons of trapped water can crack the housing.
A few older lakefront places still pull water straight from the lake. Those intake lines should be disconnected, drained back toward the water, and stored above the ice line before freeze-up.
Leave the Heat at 50 or Drain It Down?
Some owners skip the drain-down and leave the furnace set at 50 degrees instead. It works until something fails. A propane furnace holding 50 in a modest cottage burns roughly $150 to $300 a month, so heating a vacant building from November through March adds $750 to $1,500 a season.
Reliability is the bigger problem. One ice storm can cut power for three days, and a furnace that quits in an empty house gives no warning at all. Insurance adjusters see this exact failure every winter, and some carriers now require proof of maintained heat or a documented winterization on seasonal homes.
A full drain-down costs almost nothing after the first season and removes the risk entirely. If you keep the heat on anyway, add a freeze alarm or WiFi thermostat that sends an alert when the indoor temperature drops below 40.
What a Plumber Charges Versus Doing It Yourself
Professional winterization for a typical two-bathroom cottage runs $150 to $350 in most Michigan markets, with the compressor blow-out included. Larger homes with boilers, multiple zones, or in-floor heat can run $400 to $700 because hydronic systems take more time and care.
Doing it yourself costs $30 to $60 for four or five gallons of RV antifreeze, plus the one-time purchase of a small compressor if you want blown-out lines. The math favors DIY after that first season.
Paying a licensed local plumber for year one is still money well spent. Watch the pro work through your specific cottage, take notes on where every drain valve and low point hides, and the job becomes yours from then on.
Reopening in the Spring
Spring startup is the shutdown run in reverse, done slowly. Close every faucet you left open, restore water at the main valve or the pump breaker, then walk the whole system listening for hissing or dripping before you call it good.
Fill the water heater completely before restoring its power, because electric elements burn out within seconds when energized dry. Run each faucet until the pink antifreeze clears, flush the toilets several times, and run a rinse cycle through the dishwasher and washing machine.
Check the crawl space with a flashlight while the system holds pressure. More seasonal home care guides are available if you want a fuller spring checklist to work from.
The Mistakes That Turn Into Insurance Claims
Outdoor spigots cause more cottage claims than any other single item. A frost-free hose bib only protects itself when the hose is removed, so a forgotten garden hose traps water in the stem and splits the pipe inside the wall.
Ice maker lines are the second repeat offender. The thin quarter-inch line feeding the refrigerator holds water nobody remembers, and it runs through cabinetry where a slow leak can soak the subfloor for months. Disconnect it at the supply valve and drain it toward the fridge.
Traps are the sneaky one. The water sitting in every P-trap will freeze and crack the fitting, which is the whole reason for the RV antifreeze step, and a cracked trap lets sewer gas seep into the cottage all winter.
Frequently Asked Questions
How much RV antifreeze does a typical cottage need?
Plan on four to five gallons for a two-bathroom cottage with a washer and dishwasher. Each toilet takes about a half gallon between tank and bowl, and each trap takes a cup or two. Buy an extra jug, since sealed leftovers keep fine for next season.
Can I pour antifreeze into the supply lines instead of draining them?
No. Supply lines need to be drained or blown out, since filling them would take dozens of gallons and still leave air pockets where water collects. Antifreeze belongs only in the places designed to hold standing water: traps, toilet tanks and bowls, and appliance drains.
When should I book a plumber for winterization?
Call by late September for a mid-October slot. Cottage-country plumbers book out two to three weeks at peak, and some offer 10 to 15 percent off for closings scheduled before the rush hits.