Smoke and CO Detectors: Placement, Age and Replacement

Detectors expire, get painted over and end up in the wrong rooms. A short guide to where they go, how old is too old, and the hardwired swap.

Smoke detectors are on nearly every handyman list we get, usually as "the one that keeps chirping." The chirp is worth taking seriously, but it is also the least of what is usually wrong. On most service calls we find detectors that are past their service life, missing from rooms that should have them, or painted over so thoroughly they could not sense a bonfire. Here is a plain guide to getting them right.

Detectors expire

A smoke detector's sensor degrades. Manufacturers state a service life, commonly around ten years for smoke alarms and shorter for many carbon monoxide alarms, and the date of manufacture is printed on the back. A detector past that date should be replaced regardless of whether it still beeps when you press the test button, because the test button checks the horn and the circuit, not the sensor. If you cannot find a date, or the unit is yellowed, it is old enough.

Where they go

• Inside every bedroom.
• In the hallway outside the bedrooms. One per sleeping area.
• At least one on every level, including a finished bonus room over the garage.
• Not in the kitchen or within several feet of a cooktop, where nuisance alarms lead to disconnected units. Near the kitchen, a photoelectric unit is less prone to false alarms from cooking.
• Not in the garage or bathroom, where exhaust and steam cause false alarms.
• On the ceiling or high on the wall, away from the dead air in corners and away from AC supply vents that blow smoke past the sensor.

Carbon monoxide

Many Central Florida homes are all-electric, and homeowners assume CO is not a concern. It still is if you have a gas water heater, a gas range, a gas dryer, a fireplace, an attached garage, or a generator you might run after a storm. Generators are the real Florida CO risk. Every hurricane season brings CO poisonings from generators run in garages or too close to open windows. A CO alarm near the sleeping area, and one near any fuel-burning appliance, is cheap protection. Combination smoke and CO units simplify the count.

Testing and cleaning

Press the test button on every detector monthly. It confirms the horn and the power, and in an interconnected system it confirms the others respond. Vacuum the vents gently a couple of times a year; dust, cobwebs and the fine grit that comes with Florida pollen season collect on the sensor and cause both false alarms and missed ones. If a detector goes off repeatedly with no smoke, do not pull the battery and leave it; move it or replace it with a photoelectric unit.

Hardwired versus battery

Homes built in the last few decades in Polk County usually have hardwired, interconnected detectors, so when one sounds they all sound. When replacing these, use a unit compatible with the existing wiring harness, or swap the harness. Battery-only units are fine in older homes without wiring, and wireless-interconnect battery units now give the same all-sound benefit without running wire. Ten-year sealed-battery units eliminate the yearly battery change and the 3 a.m. chirp, which is why we recommend them.

The painted-over problem

A detector that has been painted, even a light coat during a ceiling repaint, has its vents clogged and should be replaced, not cleaned. Painters should remove or bag detectors, and we do. Our post on removing popcorn ceilings is one job where detectors always come down first.

The rest of the safety list

While we are up on the ladder, a few other items are worth a look: a fire extinguisher in the kitchen and garage, a working GFCI on the bathroom, kitchen, garage and exterior outlets, and a clear path from every bedroom window in case it is needed as an exit. Older homes sometimes have windows painted shut or security bars without a quick release, and both matter. These are all part of the checklist we run on a newly bought house.

Getting it done

Replacing every detector in a house is a short visit and one of the least expensive jobs on any list. Inventive Home Improvement handles it as part of our handyman services and home maintenance across Lakeland, Davenport, Lake Wales and all of Polk County. Call (863) 633-5499 or request a free estimate.

Frequently asked questions

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