December Home Maintenance Checklist: Mostly Holiday Safety

December ties with July as the lightest month on the maintenance calendar: check every cord and light strand before you plug it in, make sure the fireplace and any space heaters are safe to run, test the smoke and CO alarms, inspect the HVAC filter, and start watching the roofline for ice dams. Do those five things and you've done December.

The list is short because the stakes concentrate. No other month stacks fire risk like this one: a drying tree wrapped in lights, cords under rugs, candles, space heaters, and a fireplace at peak use. Our winter maintenance guide covers the season end to end; this page is only what matters right now.

Check the holiday lights and cords before anything goes up

The formal whole-house cord audit lands on January's list; December's version is triage for whatever comes out of storage. Before a strand goes on the tree or the eaves, run its length through your hands looking for fraying, cracked insulation, or crushed sections, then plug it in and feel the plug after a few minutes. Warm or damaged means retired.

Then check the connections. Outdoor lights need outdoor-rated cords on GFCI-protected outlets. Don't chain extension cords, and don't route them under rugs or through pinched door gaps. A temporary cord should not become permanent wiring; ask an electrician about a suitable receptacle when the setup does not have safe permanent power.

And if you have a live tree, water it daily; a dry tree burns shockingly fast.

Make the fireplace and space heaters safe to run hard

If you burn wood and the chimney has not had its annual inspection, arrange one with a qualified chimney professional before regular use. Cleaning and repair depend on fuel, deposits, damage, appliance, and the installed system. Ask for a local quote after the inspection defines the work.

If the gas fireplace missed its fall service, book it before regular use. CPSC recommends yearly professional inspection of fuel-burning fireplaces and their venting. The technician should follow the installed model's manual; homeowners should not open sealed glass, move logs or media, test gas connections, or service gas or electrical components unless that manual assigns the step to them.

Space heaters get three rules and no exceptions: well clear of anything that can burn (curtains, bedding, the couch), plugged straight into a wall outlet rather than a cord or power strip, and off when you leave the room or go to sleep.

Test every smoke and CO alarm

Press the test button on every smoke and carbon monoxide alarm and confirm each one sounds. This is a monthly task, not a December-only check. Follow the exact model instructions when a unit stays silent. Smoke alarms are generally replaced 10 years after manufacture; CO alarm replacement dates vary by model, so use the printed date or end-of-life signal rather than a universal lifespan.

Inspect the HVAC filter and give the heat a once-over

With the system running long hours, inspect the filter this month. Clean or replace it when dirty and at the interval stated by the filter or equipment manufacturer. Thickness alone does not define a safe service interval. The HVAC maintenance schedule covers the full year.

Two system-specific checks while you're at it:

• Heat pump: from a safe distance, look for ice that persists rather than clearing during normal operation. Brief frost, steam, and defrost can be normal. Contact a qualified technician if ice remains or heating performance drops.
• Boiler: compare the visible gauge or sight glass with the installed manual. Report leaks or a sustained change; do not use a universal pressure target or bleed a pressurized system unless the owner instructions provide that procedure.

Use the first snow to learn your roof

In zones where snow persists, compare roof-snow patterns with prior winters from the ground. Uneven melt, an ice ridge, leakage, or changed attic moisture can justify qualified review, but the pattern alone does not identify the cause. Air leakage, insulation, ventilation, roof geometry, sun, wind, and weather can all affect what you see.

That baseline is the whole December job; insulation and ventilation work belonged in fall. If a ridge is forming, stay off the roof. A nonmetal roof rake may be appropriate from stable ground when it will not contact conductors or damage the roofing, but FEMA says roof-snow removal generally belongs to qualified people. Hardened ice, unsafe access, or an interior stain needs prompt professional assessment.

Ten-minute extras if you have the time

• Observe gutter guards if November's service skipped them. From the ground, look for piled debris, movement, and overflow. Have a qualified gutter service clear elevated guards according to the installed product; do not use a blower or brush from a roof edge.
• Review dishwasher care before heavier holiday use. Check the manual to learn whether the model has an owner-cleanable or self-cleaning filter, how removable parts come out, and which cleaner or maintenance cycle is approved. Rinse and brush an owner-removable filter as directed and confirm dishes do not block spray-arm movement. Do not force parts off or add vinegar unless the manual permits it.
• Run a radon test. December may make a short-term test's closed-building conditions easier to maintain, but a winter result is not guaranteed to be the annual high. Follow the device instructions. The EPA recommends fixing a home at 4 pCi/L or above and considering action between 2 and 4 pCi/L.

Living somewhere warm? Your December may be outside

Mild weather can make December useful for a ground-level exterior review. Look for pest activity and identify the pest before choosing any treatment. If a pesticide is warranted, follow the label, protect people and pets, and prevent drift or runoff. Also look for dead, broken, hanging, or rubbing branches; contact with the home; blocked access; and utility conflicts. Pruning timing and clearance depend on the species, condition, structure, and local guidance. Contact the utility for line conflicts and use a qualified arborist for large, elevated, damaged, or uncertain work.

Common questions

Is it safe to leave holiday lights on overnight?

Interior lights on a live tree, no; a dry tree plus warm lights plus nobody awake is the classic December fire scenario. Exterior LEDs on outdoor-rated cords are lower risk, but an inexpensive outlet timer removes the question for both.

I only use the fireplace a few times each winter. Do I really need a sweep?

You need at least an inspection. Creosote accumulates by the fire, not by the calendar, but cracked flue liners, failed dampers, and animal nests don't care how often you burn. The inspection also tells you whether the full cleaning can wait.

How do I know if ice on my roof edge is actually a problem?

Icicles alone aren't a verdict. A continuous band of ice at the eave, ice creeping upslope from the roof edge, or fresh stains on upstairs ceilings near exterior walls all mean water is pooling behind ice, and it's time for a roof rake or a removal call.

A short month is the easiest one to skip entirely, which is how the fireplace goes unswept for a third year. SeasonKeep turns this into dated reminders built from your zip code and systems, free to start, and the January checklist picks up where the holidays leave off.