How much does it cost to replace smoke and CO alarms?
Updated
Short answer
Replacing a smoke or carbon monoxide alarm yourself costs $15 to $50 per alarm, and each swap takes 15 to 30 minutes. An electrician charges $50 to $150 per alarm to replace hardwired, interconnected units. A house needs several alarms, so the whole set costs a multiple of either figure, but it's a bill that comes every 10 years for smoke alarms and every 5 to 10 for CO alarms, and the alarms are the cheapest safety equipment the house has.
Cost breakdown
| Item | DIY | Pro |
|---|---|---|
| Materials | $15 to $50 | included |
| Tools you may need to buy | none | included |
| Labor | your time | $50 to $150 |
| Total | $15 to $50 | $50 to $150 |
Both columns are per alarm. The DIY column is the alarm itself, from a basic battery smoke alarm to a combination smoke and CO alarm with a sealed 10 year battery. The pro column is an electrician's labor per hardwired alarm, which drops per unit when a whole house is done at once.
What drives the cost
- The alarm type. A battery smoke alarm is the low end. A combination smoke and CO alarm, a sealed-battery unit, or a hardwired alarm with a battery backup is the high end.
- Hardwired or battery. A battery alarm screws to the ceiling and is done. A hardwired alarm plugs into house wiring, and if the connector doesn't match the old one, an electrician's visit follows.
- How many. A house needs an alarm in every bedroom, outside each sleeping area and on every level, so the count is usually several, and buying a multi-pack brings the per-alarm price down.
- Interconnection. Alarms that trigger each other have to be compatible, which can mean replacing the whole set as a matched kit.
- The electrician's trip. A single hardwired alarm costs the full call-out rate. A whole house replaced in one visit spreads it.
DIY vs. pro
Battery alarms are a DIY job, and hardwired ones usually are too, since most replacements use the same mounting plate and plug-in connector as the old alarm. How often to replace smoke and CO alarms is every 10 years for smoke and every 5 to 10 for CO, by the date on the back, and the money strongly favors doing it yourself at $15 to $50 per alarm.
Call the electrician when the connector doesn't match and the wiring has to be changed, when the alarms are on a high ceiling, or when a whole house of interconnected alarms is being replaced and you want them tested as a system. At $50 to $150 per alarm, done all at once, that's a fair price for a job that's done right and done rarely.
FAQ
How much does a smoke alarm cost?
$15 to $50, from a basic battery alarm to a combination smoke and CO alarm with a sealed battery.
How much does an electrician charge to replace smoke alarms?
$50 to $150 per alarm for hardwired units, and less per unit when the whole house is done in one visit.
Can I replace hardwired smoke alarms myself?
Usually, if the new alarm fits the existing plug-in connector. Turn off the breaker first. A connector that doesn't match is an electrician's job.
Is it cheaper to buy smoke alarms in a pack?
Yes. A multi-pack of matching alarms costs less per unit and guarantees that interconnected alarms work together.