Check the age of every smoke detector
One-time · any month works
Why it matters
Here's the thing your semiannual button-test can't tell you: the test button proves the battery and the horn work — not the smoke sensor. Sensors degrade with dust, humidity, and time, and the industry's hard line is ten years. Past that, a detector can pass every button test you give it and still sleep through smoke.
What skipping it costs
$0–$50,000
Detector sensors wear out at about ten years whether or not the test button still beeps — the button tests the horn and battery, not the sensor. The priced part of neglect is the difference between a room fire and a house fire; the unpriced part is why this audit exists.
Two ways to get it done
Do it yourself
You'll need: Step stool, Phone camera, Replacement detectors as needed (~$15–$40 each; sealed 10-year units ~$25–$50).
- Take each detector down (twist off the base) and photograph the back. There's a manufacture date printed on every one.
- Do the math: ten years from the _manufacture_ date, not the install date. Expired or unreadable → replace.
- While you're up there, note the type on the label: hardwired with a plug harness, or battery-only. Photograph the harness if hardwired — it makes buying compatible replacements painless.
- Buying replacements: sealed 10-year-battery units cost a bit more and end the 2 a.m. chirp era forever — worth it for battery-only locations. For hardwired, match the interconnect (same brand family, or check compatibility lists).
- Placement check while you're at it: one inside each bedroom, one outside sleeping areas, one per level. Kitchens get photoelectric near — not directly over — the cooking.
- Log the new dates in your house details and set this audit to repeat when they age out.
Hire it out
$150–$350National fair range — local labor moves this number.
For a house full of hardwired, interconnected detectors, an electrician or handyman visit runs $150–$350 to swap the lot — the harnesses clip in, so you're mostly paying for ladder time and disposal.
This is one of the cleanest jobs in the trades, which is why the upsell pressure comes from outside it: detector swaps are a favorite doorway for monitored-alarm sales. Monitoring has its uses, but it's a separate decision made on your schedule — not at the top of a ladder with your old detector in someone's hand.
Ask the tech
- Are these interconnected, and will the replacements talk to each other the same way?
- Are you matching the existing wiring harness or rewiring the base?
- Photoelectric, ionization, or dual-sensor — and why for each location?
Red flags you're being upsold
- A detector swap that becomes a monitored-security-system pitch. Detectors are $25 hardware, not a $40/month subscription decision.
- Quotes over $75 per unit to swap hardwired detectors — the harness clips in like a lamp plug.
- Anyone who suggests capping a 'nuisance' detector instead of relocating or replacing it.
Second opinion time: Any whole-system replacement quote over $1,000 for a typical house — count the ceilings and do the math first.
The call
DIY it — every detector has its birthday printed on the back. Ten years old means replace, no exceptions, no matter how clean it looks.