Smoke and Carbon Monoxide Detector Installation
A hardwired smoke alarm is not a battery unit screwed to the ceiling. It runs on the house wiring, it talks to every other alarm in the house, and ten years after it was made it is due to come down, whether it still chirps or not.
Interconnected is the point
When a hardwired alarm in the basement detects smoke, every alarm in the house sounds, so the people asleep two floors up hear it too. That only works if the alarms can talk to each other. Most brands interconnect only with their own line, which is why one mismatched replacement can leave the upstairs silent.
Every smoke alarm carries a manufacture date on the back, and the national fire alarm code calls for replacing it ten years after that date. Carbon monoxide alarms wear out on their own schedule, printed on the unit. In a house where the alarms went in with the original construction, that usually means all of them at once, as a matched set.
What moves the price of smoke and CO alarm work
We do not publish a dollar figure we cannot stand behind. What we can tell you is which parts of the job move the number.
| Job | Relative cost | What drives it |
|---|---|---|
| Replacing hardwired alarms on existing wiring | Baseline | Matched, interconnected replacements on the boxes and wiring already there. Priced mostly by the count. |
| Changing to a different brand | Slightly higher | Brands rarely interconnect with each other, so a change of brand means changing the whole set and its connectors together. |
| Adding alarms where none are wired | Higher | A new box and a run for each location, plus the interconnect. Attic and basement access decide it. |
| Combination smoke and CO alarms | Depends on the house | Carbon monoxide alarms belong in homes with fuel-burning appliances or an attached garage. Combination units cover both in one device. |
| Alarms for a remodel or addition | Part of the job | When a house is added onto or remodeled, the code usually brings the alarms in the work area up to current rules. We wire them with the rest of the job. |
We count the alarms, check the brand, the dates and the interconnect, and give a flat price.
What to Expect
Count and date them
How many alarms, where, which brand and how old. The date on the back decides what has to come down.
Check the interconnect
Whether the wiring links them, and which replacements will talk to each other.
Replace as a set
Matched alarms, new connectors, mounted on sound boxes.
Test them together
Press one test button and every alarm in the house should sound. We check that before we leave.
Questions We Get
How many smoke detectors do I need?
One in every bedroom, one outside each sleeping area, and one on every level of the house, basement included. A two-story, three-bedroom house with a basement typically needs at least six. Large or split floor plans can need more.
Where should a carbon monoxide detector be installed?
Outside each sleeping area, close enough to wake the people in the bedrooms, and on levels with fuel-burning appliances. Follow the maker’s height and distance guidance; combination smoke and CO alarms mount on the ceiling like a smoke alarm.
Do you install fire alarms?
In a house, yes: the hardwired smoke alarms most people call fire alarms, interconnected so one sounds them all. Commercial fire alarm systems with a monitored control panel are a separate specialty; ask and we will tell you straight whether it is one we take on.
How much does it cost to replace hardwired smoke detectors?
Mostly the count. Replacing a matched set on existing wiring is the simplest version. Adding alarms where there is no wiring, or changing brands, takes more. We quote flat after counting them and checking the interconnect.
Why is my hardwired smoke detector chirping?
Usually the backup battery is low, or the alarm has reached the end of its life and is saying so; many alarms use a different chirp for each. Replace the battery first. If it keeps chirping and the alarm is near or past ten years old, it is due for replacement, and so are the others installed with it.
Can I replace a hardwired smoke detector with a battery one?
Generally, no. Where a house was built with hardwired, interconnected alarms, the replacements should be hardwired too. A battery-only unit cannot set off the others, which is the whole reason the house was wired for them.
Do all my smoke detectors have to be the same brand?
For hardwired alarms to interconnect, usually yes. Most manufacturers interconnect only with their own line, so replacing one alarm with another brand can quietly break the chain. We replace them as a matched set.
Where should smoke detectors be placed?
Current residential code calls for one in every bedroom, one outside each sleeping area, and one on every level, basement included. Carbon monoxide alarms go outside sleeping areas in homes with fuel-burning appliances or an attached garage. The code edition your city enforces sets the details.
Do you install carbon monoxide detectors?
Yes, hardwired and combination smoke and CO alarms. If your house has a gas furnace, water heater, range or fireplace, or an attached garage, it should have them.
Ready to Get Started?
Call, text, or request a free quote online — we typically respond within one business day.