The Colorado rental maintenance year, month by month

Reactive maintenance is the most expensive way to own rental property, and Colorado punishes it harder than most states. Almost every emergency call on the Front Range is a predictable seasonal failure that arrived on schedule.

This is the calendar. Adjust for elevation — Boulder County and the foothills run a few weeks ahead of the metro on the cold end.

Spring: March to May

• Turn on and test irrigation once the freeze risk passes. Check every head, look for winter breaks, verify the backflow preventer.
• Commission the swamp cooler if the property has one. New pads, clean the reservoir, check the float valve, verify the water line. A stuck float floods a ceiling.
• Service the AC before the first hot week, not during it.
• Inspect the roof after the first hail and photograph it. Even minor bruising matters later.
• Clear gutters of winter debris ahead of spring storms.
• Walk the exterior for freeze-thaw damage — concrete cracks, mortar, caulking, window seals.

Summer: June to August

• Hail season peaks. After any significant storm, inspect the roof, gutters, siding, window screens and any AC condenser. Photograph and date everything.
• Mid-year interior inspection. Under sinks, around toilets, water heater base, ceilings below bathrooms. Catching a slow leak here saves a five-figure remediation.
• Check the water heater — age, corrosion, drip pan, and the TPR valve.
• Trim vegetation back from the structure and the roofline.
• Verify smoke and CO alarms. Batteries and expiry dates, not just a test button.

Fall: September to November — the critical window

This is the month that matters most, and the deadline is real rather than advisory.

• Blow out the sprinkler system before the first hard freeze. Not "when it gets cold" — before. A freeze in an undrained system cracks the backflow preventer and often the underground lines. This is the single most common avoidable four-figure repair in Colorado.
• Winterize the swamp cooler — drain it, disconnect and drain the water line, cover the unit. A live line to an uncovered cooler is a burst pipe waiting for a cold snap.
• Service the furnace and change the filter. Do this in September. A no-heat call in January starts a habitability clock measured in hours, and every HVAC company in the metro is booked when that happens.
• Disconnect and drain exterior hose bibs. A hose left attached over winter bursts the pipe inside the wall.
• Clean gutters after leaf drop. Blocked gutters cause ice dams, and ice dams cause interior water damage.
• Check weatherstripping and seals. Cheap, and it shows up in the tenant's heating bill.

Winter: December to February

• Watch for ice dams after heavy snow followed by sun. Icicles along a roof edge are a warning, not a decoration.
• Confirm heat is working at every property early in the season, ideally by asking tenants directly rather than waiting to be told.
• Check for frozen pipe risk in unheated crawl spaces, garages and vacant units. A vacant property in January needs the heat left on.
• Keep snow removal covered where it is your responsibility. Slip-and-fall liability is real and winter is long.

Annually, whenever suits

• Radon test. Much of the Front Range sits in a high-radon zone. Colorado requires disclosure, and mitigation is a modest cost against a genuine health risk. Test once and know where you stand.
• Dryer vent cleaning. Fire risk, and tenants never do it.
• Full interior and exterior inspection with photographs. This is your documentation for insurance, for deposits and for habitability.
• Review insurance coverage. Front Range hail has pushed premiums and deductibles up sharply — see our landlord insurance guide.

Why this is worth the trouble

Every item above is cheaper than what it prevents. A sprinkler blowout costs a fraction of a cracked backflow preventer. A furnace service costs a fraction of an emergency January call-out — and far less than the habitability exposure of a delayed repair. See our habitability guide for what those deadlines actually are.

The other benefit is less obvious: tenants who see a property being maintained treat it better and stay longer. Turnover is the largest cost in rental ownership, and the cheapest way to reduce it is to be visibly competent.

One more boundary item worth knowing before you replace anything: Colorado fence laws — most disputes are really survey disputes, and HOA and city rules usually control what you may build.