West Michigan’s first hard freeze typically arrives between mid-October and early November — sometimes earlier. The window to prepare your home’s plumbing for winter is September and early October, before the ground is frozen and before plumbers’ schedules fill with emergency calls. This 8-step checklist covers everything you need to do before cold weather arrives: outdoor faucets, sump pump, pipe insulation, water heater, irrigation blowout, and more.
September feels like summer’s not quite over — but the calendar doesn’t lie. Grand Rapids has seen its first freeze as early as October 7. Homeowners who complete their plumbing winterization in September have their pick of appointment times and the peace of mind that comes with being done. Homeowners who wait until the forecast drops to 28°F call us in a panic, competing with every other homeowner in West Michigan who also waited.
This checklist is the definitive September plumbing prep guide for Michigan homeowners. It picks up where our end-of-summer plumbing checklist left off in August. Work through it systematically and you’ll head into winter in the best possible shape. More seasonal guides are in the Kenowa Plumbing Resources & Guides library.
🚰 Step 1: Shut Off and Drain All Outdoor Water Lines
Every outdoor hose bib and supply line that isn’t frost-free must be shut off from the interior and drained before the first freeze. Water left in an outdoor line that freezes will expand, crack the pipe, and either leak into your home’s wall cavity or burst when the thaw arrives. This one step prevents the most common and most expensive winter plumbing emergency in West Michigan.
How to do it correctly:
- Locate the interior shutoff for each outdoor faucet — typically in the basement, often on the same wall as the outdoor fixture
- Turn the interior shutoff fully closed
- Go outside and open the outdoor faucet handle — this drains any remaining water from the section of pipe between the shutoff and the faucet. Leave it cracked open until drainage stops, then close it
- Disconnect and store all hoses — a hose left connected to a frost-free faucet traps water in the stem and defeats the frost-free design
- For standard (non-frost-free) bibs: the above steps are essential. For frost-free bibs: disconnecting hoses is all that’s typically needed — the stem drains automatically when the handle is turned off
For a deeper dive on outdoor faucet types: Outdoor Faucet & Hose Bib Repair in Michigan: Spring Startup Guide.
🌿 Step 2: Winterize Your Irrigation System
In-ground irrigation systems must be winterized before the first hard freeze by blowing compressed air through every zone to remove all water from the lateral lines and heads. Water left in an irrigation system will freeze and crack heads, lateral lines, and potentially the backflow preventer — a $500–$1,500 repair for what is a $75–$125 preventive service call.
The winterization process:
- A licensed irrigation technician or plumber connects a high-volume air compressor to the system through a blow-out port
- Each zone is opened and blown out individually until no water vapor exits the heads — typically 2–3 passes per zone
- The backflow preventer is drained and the isolation valves on either side are closed
- The controller is set to rain/off mode for the season
Book your irrigation blowout appointment in September — Kenowa Plumbing’s October schedule for irrigation winterization typically fills by mid-September.
💧 Step 3: Test and Inspect Your Sump Pump
Sump pump failures don’t announce themselves in advance. A pump that sat dormant through a dry August and seems fine may have a seized impeller, a float switch stuck in position, or a battery backup that hasn’t been charged in two years. September is your last good window to test it, replace it if needed, and address any backup power concerns before fall rain season peaks.
- Pour water into the pit until the float rises — confirm the pump activates, moves water, and shuts off
- Check the discharge line at the exterior — confirm it terminates at least 10 feet from the foundation and isn’t obstructed by overgrown vegetation
- Test the battery backup (if equipped) — most batteries need replacement every 3–5 years
- Note the pump’s age — proactively replace at 10+ years rather than waiting for a failure during a storm
🌡️ Step 4: Insulate Vulnerable Pipes
Michigan’s 42-inch frost depth and prolonged sub-freezing temperatures create real freeze risk for any pipe that runs through an unheated space. Identifying and insulating vulnerable pipes in September takes an hour and costs $20–$100 in foam pipe insulation from any hardware store — and prevents a burst pipe repair that starts at $500 and can reach $15,000 if water damage occurs.
Highest-risk locations to check:
- Crawl spaces: Any supply pipes running through an uninsulated crawl space are at risk in prolonged cold snaps. Foam pipe insulation should cover the full length of exposed pipe
- Attached garages: Pipes running through an unheated attached garage — particularly supply lines to an exterior wall faucet — need insulation and ideally a dedicated interior shutoff
- Exterior wall cavities: Supply pipes running through exterior walls in older Michigan homes with inadequate insulation can freeze during extended cold below 0°F. Cabinet doors under kitchen sinks on exterior walls should be left open during extreme cold events
- Basement perimeter pipes: Supply pipes running along the rim joist area at the top of the foundation wall are particularly exposed — insulate the rim joist and any pipes in this zone
🔥 Step 5: Service Your Water Heater
Incoming water temperature in Grand Rapids drops from roughly 65°F in summer to 45°F in winter. Your water heater must raise cold water 75°F instead of 55°F, running longer cycles and using significantly more energy. A water heater burdened with sediment from a year of West Michigan hard water is doing this inefficiently. A fall flush and inspection gets it running clean before peak demand.
- Schedule a water heater flush to clear sediment from the tank bottom
- Check the T&P relief valve: test the lever briefly — if it doesn’t spring back or water doesn’t stop flowing, the valve needs replacement
- Inspect the first few inches of the cold-in and hot-out supply connections for corrosion or moisture
- Note the manufacture date — any water heater 10+ years old should be on your replacement planning radar
- Consider adding a water heater insulating blanket for older tanks in unheated utility rooms — reduces standby heat loss
For water heater efficiency strategies beyond the flush, see Water Heater Efficiency in Michigan: How to Lower Your Energy Bills This Winter.
🔧 Step 6: Check the Pressure Regulator and Main Shutoff
The pressure regulator (a bell-shaped device on the main supply line where it enters the home) controls household water pressure. A failing regulator allows pressure to creep too high — accelerating wear on all fixtures and appliances. The main shutoff is your emergency stop — the valve that cuts all water to the house instantly in a burst pipe scenario. Both should be tested and confirmed before winter.
- Pressure regulator: Attach a gauge to a hose bib — normal pressure is 45–80 PSI. Above 80 PSI indicates a failing regulator ($200–$450 to replace). Below 40 PSI indicates either regulator failure or supply line restriction
- Main shutoff: Turn it off fully and then back on. It should operate smoothly without stiffness. A valve that won’t fully close — or that requires significant force — should be replaced before winter, not discovered during an emergency
🏠 Step 7: Prepare for Vacant Periods
Michigan homeowners who travel in winter, own vacation properties, or manage rental units with any vacancy between November and March need a vacant-home winterization plan. A home with no heat source that drops below freezing will have burst pipes — guaranteed. The damage from burst pipes in a home discovered weeks after the freeze starts at $10,000 and can reach $50,000+ in severe cases.
For homes that will be occupied all winter: set the thermostat to a minimum of 55°F even when away. For homes that will be vacant:
- Shut off the main water supply
- Open every faucet to drain the supply lines
- Flush every toilet to empty the tank and bowl
- Add RV-grade propylene glycol antifreeze to toilet bowls, tanks, and all P-traps (sinks, showers, floor drains) to prevent freeze damage to traps
- Drain the water heater if the home will be vacant for more than 2–3 weeks
- Kenowa Plumbing offers professional vacant-home winterization service — a single visit that covers the complete shutdown procedure and provides a written record of the work
📱 Step 8: Know Your Emergency Contacts and Shutoff Locations
The 30 seconds it takes to shut off the main water supply is the difference between a minor repair and a major restoration project. September is the time to make sure every adult in your household knows where the main shutoff is, how to operate it, and who to call for emergency plumbing service. Post Kenowa Plumbing’s number near your shutoff valve and in your phone contacts now.
- Locate and label the main water shutoff
- Confirm all household members know its location and can operate it
- Know the location of individual fixture shutoffs under sinks and behind toilets
- Save Kenowa Plumbing’s emergency service number in your phone: (616) 538-5929
- Know your Consumers Energy emergency number for gas issues: 1-800-477-5050
Fall Prep at a Glance: Schedule and Priority
| Checklist Item | Who Does It | When |
|---|---|---|
| Outdoor faucet shutoff and drain | DIY — 30 minutes | Complete by October 1 at the latest |
| Disconnect and store all hoses | DIY — 10 minutes | Same day as faucet shutoff |
| Irrigation system blowout | Professional — schedule now | Must be done before first hard freeze (~Oct 15) |
| Sump pump test | DIY test; pro if issues found | September — don’t wait for fall rain season |
| Pipe insulation check and add | DIY — 1–2 hours + materials | Before October; urgent if crawl space pipes exposed |
| Water heater service | Professional — schedule now | September/early October |
| Pressure regulator and shutoff check | DIY test; pro if issues found | September |
| Vacant home winterization plan | Professional if full shutdown | Before any extended absence November–March |
| Emergency contacts posted | DIY — 10 minutes | This week |
Frequently Asked Questions
Plan to have outdoor faucets shut off and irrigation winterized by October 10 at the latest. Grand Rapids’s average first freeze date is late October, but early freezes in the first two weeks of October happen several times per decade. Completing the checklist in September gives you a two-week buffer and access to appointment slots that disappear by early October.
You got lucky — or you have frost-free bibs that protected you. Frost-free faucets tolerate many winters without failure even when hoses are left connected, but a hose left on a frost-free bib in a hard enough freeze will still cause failure. Standard bibs without a dedicated shutoff will eventually fail. The cost of a $75–$150 repair is negligible compared to what a burst pipe inside the wall costs — it’s a risk-to-cost calculation strongly in favor of completing the checklist.
Technically yes, but the compressor requirements are specific — a high-volume, low-pressure compressor (not a standard shop compressor) is required to safely blow out irrigation lines without damaging heads or fittings. Overblowing an irrigation system with excessive pressure is a common DIY mistake. Kenowa Plumbing uses the correct equipment and completes the job in one visit — the cost savings from DIY are marginal.
