Carbon monoxide detector installation cost
Adding missing carbon monoxide (CO) detectors and replacing ones that don't work.
Carbon monoxide (CO) is a gas you can't see or smell. Gas furnaces, water heaters, stoves, fireplaces and attached garages can all produce it. A CO detector sounds an alarm before levels get dangerous.
The Consumer Product Safety Commission says CO detectors go on every floor and outside sleeping areas. Combination smoke and CO detectors cover both in one unit: see smoke detectors and where to put smoke and carbon monoxide detectors.
What our reports priced these at
| Work | Most homes | Middle price | Based on |
|---|---|---|---|
| Install smoke and/or CO detectors | $190 to $390 | $280 | The 41% of homes where it was priced |
| Install a CO detector | $150 to $240 | $150 | Limited number of homes |
What HomeCloud reports priced this fix at in homes we evaluated Sep 2025 to Oct 2026. The range is the middle half of homes; the middle price is the median. Your price comes from a written estimate for your home.
What affects the price
- How many detectors
- Homes with more floors and bedroom areas need more detectors.
- Plug-in, battery or hardwired
- Plug-in and battery detectors install quickly. Hardwired ones may need new wiring.
- Combination detectors
- Replacing separate smoke and CO detectors with combination units can mean fewer devices to maintain.
Common questions
Does my home need a CO detector if it's all electric?
Homes with no gas, oil or wood-burning appliances and no attached garage have fewer sources of carbon monoxide. Your report says where a detector is recommended.
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