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Kidde 900CUAR Hardwired Interconnectable Smoke & CO Alarm
$53.99
$54.99
Final price set by Amazon · may vary
EDITORIAL REVIEW: 4.5/5 — WC Safety Review of the kidde 900cuar, a combination smoke and CO alarm. Editorial assessment by Steven Eaton, WC Safety editor, based on published Kidde specifications and category fit. We...
Key Features
- 24/7 Self-testing components are always checking the device to ensure it's operating as expected (not a substitute for a manual push test)
- Easy installation mounting bracket included for quick installation in 4 orientations
- Photoelectric sensor detects visible fire particles associated with slow, smoldering fires, while the electrochemical sensor detects carbon monoxide
- 85-decibel alarm & LED warning indicators alert you to various status: green = normal operation, amber = operating error, and red = smoke, fire or carbon monoxide event
- Battery operated to provide reliable detection, even during power outages; two AA batteries included
- UL Listed with a 10-Year limited manufacturer warranty on the alarm only (not a battery performance claim)
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Built for Industrial BuyersResearch written for safety managers, procurement teams, and field supervisors.
EDITORIAL REVIEW: 4.5/5 — WC Safety Review of the kidde 900cuar, a combination smoke and CO alarm.
Editorial assessment by Steven Eaton, WC Safety editor, based on published Kidde specifications and category fit. We did not laboratory-test this product.
Editorial assessment by Steven Eaton, WC Safety editor, based on published Kidde specifications and category fit. We did not laboratory-test this product.
The Kidde 900CUAR is a hardwired, interconnectable combination smoke and carbon monoxide alarm - wire several together and one detection sounds them all.
CHECK PRICE ON AMAZON → SHOP SMOKE & CO ALARMS →
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Why the kidde 900cuar covers both smoke and CO
A whole-home safety system is strongest when every alarm covers both hazards and all of them sound together. The Kidde 900CUAR combines dual-hazard sensing with hardwired interconnect. As smoke & CO alarms go, this is the hardwired combo interconnect pick, and the best CO detector guide and the best smoke detectors guide put it in context. It sounds the whole house for smoke or CO.
Safety first: a combination smoke and CO alarm warns of two different hazards, but it is a warning device, not suppression or a fix. If it sounds, get everyone out to fresh air and call 911. This is a residential early-warning alarm; it is not built for occupational settings where CO can reach IDLH concentrations that demand industrial gas-detection instruments and rescue procedures. Keep it powered, test it monthly, place it per the manufacturer manual and local codes, and replace the unit at its end-of-life date.
What the kidde 900cuar listing documents
From the listing: hardwired power; interconnect capability; and combination smoke and CO detection. These are true combination smoke and CO alarm and smoke and CO detector credentials as a dual-hazard alarm. Confirm the power source, UL 2034 listing, and end-of-life date on the listing. As with any life-safety device, the alarm or extinguisher is one layer of home protection — combine detection, suppression, an escape plan, and regular testing rather than relying on a single device. Buy from a listing that states the specifications and safety listings plainly, keep the paperwork, and note the manufacture and end-of-life dates when it arrives so replacement never slips, because a device past its service life can fail silently exactly when it is needed most.
How the kidde 900cuar compares
Weigh it against the First Alert SMCO410, the Huideonne XY-S510COM, the Kidde 30CUAR, the X-Sense SC01, the X-Sense SC07. The CO placement guide and the CO exposure symptoms guide help you choose.
Choosing the right home life-safety device
Match the device to the hazard and the room: smoke alarms for fire, CO alarms for combustion appliances and attached garages, combination units where you want both, and a rated extinguisher within reach of the kitchen and shop. Browse the smoke & CO alarms, carbon monoxide alarms, smoke detectors, CO detectors, smart CO alarms collections; and read the home fire safety guide to plan whole-home coverage.
Where it fits by home and orders
The Kidde 900CUAR suits new builds and remodels wiring an interconnected dual-hazard system - compare it with the Linsoal RC425COM, browse the wider carbon monoxide alarms and smoke detectors ranges, and confirm interconnect compatibility before mixing alarm models. Whole-home coverage is the goal: an early-warning device in each key room, a rated extinguisher within reach of the highest-risk spots, and a practiced escape plan tie the pieces together, so read the home fire safety guide to map what each level of your home still needs. For multi-unit or property orders, quantity purchasing runs through a free Amazon Business account — volume pricing, PO numbers at checkout, and tax-exempt eligibility for qualifying organizations, with the walkthrough linked in our footer.
Two standards, two hazards, one housing
A combination smoke and carbon monoxide alarm is listed to two separate standards, and it is worth knowing they are not interchangeable. UL 217 covers the smoke side; UL 2034 covers carbon monoxide, setting alarm response as concentration-and-time pairs and equally requiring the unit not to sound at low concentrations, so nuisance alarms do not train people to ignore it.
NFPA 72, the National Fire Alarm and Signaling Code, governs placement and interconnection. The two hazards do not want the same location — smoke rises, while CO mixes fairly evenly with air — which is the practical argument for a combination unit outside sleeping areas, and against relying on one device to cover a whole floor.
Both sensing elements have a finite life that runs from manufacture, not installation. Smoke sensors are commonly rated to 10 years and CO cells to 7–10; the unit is replaced at the manufacturer's stated end-of-life regardless of whether it still chirps.
Frequently asked questions
What is the kidde 900cuar?
A hardwired interconnectable combination smoke and CO alarm. One unit warns of both fire smoke and carbon monoxide, saving a device and a spot on the ceiling while covering two of the most common home hazards.
How is it powered?
Confirm the power source on the listing - battery, plug-in with battery backup, or hardwired. Battery-backup and sealed-battery models keep working through a power outage, which is when some CO risks rise.
Where should I place it?
Follow the manufacturer manual and local codes: generally on every level and near sleeping areas, away from dead-air spots. See our CO placement guide for room-by-room guidance.
What do I do if it sounds?
Treat every alarm as real: get everyone to fresh air outside and call 911 or the fire department, then have the CO source found and fixed by a professional before returning.
Is it the same as an industrial CO monitor?
No. This is a residential early-warning alarm. Occupational settings where CO can reach IDLH levels need industrial gas-detection instruments and rescue procedures. Use the right tool for each environment.
Does it detect both smoke and CO?
Yes - a combination unit senses both smoke and carbon monoxide and signals which hazard triggered it. Confirm the sensor types (for example photoelectric smoke plus electrochemical CO) on the listing.
How long does it last?
CO sensors have a service life, typically several years, after which the unit must be replaced, not just re-batteried. Confirm the end-of-life date and replace the alarm on schedule.
How often do I test it?
Test with the button monthly and follow the manufacturer's maintenance schedule. A CO alarm you never test is a CO alarm you cannot trust.
Can it be interconnected?
Some models interconnect so one alarm triggers all. Confirm interconnect capability and compatibility on the listing if you want whole-home alerting.
Is it UL listed?
Confirm the current UL 2034 listing on the product page. A CO alarm should carry the applicable safety listing for residential use.
Does a CO alarm replace appliance maintenance?
No - it is a last-line warning. Have fuel-burning appliances, flues, and vents inspected on schedule so CO is prevented at the source, not just detected.
How do I order several?
Quantity purchasing runs through a free Amazon Business account - volume pricing, PO numbers at checkout, and tax-exempt eligibility for qualifying organizations. The bulk-ordering walkthrough is linked in our footer.
Read our detailed Kidde 900CUAR Hardwired Interconnectable Smoke & CO Alarm review — strengths, limitations, and the alternatives that matter.
Brand / Vendor
Kidde
Model / SKU
900-CUAR
Product Type
Smoke Detector
Condition
New
MPN
900-CUAR
Price
$53.99 (Amazon)
Rating
4.3 / 5 — 2055 Amazon ratings
Availability
Check current availability on Amazon
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Coverage focuses on equipment built for professional use in manufacturing, construction, and industrial environments.
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Product information is compiled from manufacturer specifications, published standards information, compatibility data, and other cited sources.
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Verified Buyer Reviews
Customer Reviews
★★★★☆4.3 / 5· 2,055 ratings on Amazon
★★★★★
Silent, Reliable, and No More Mystery Beeps!
After finally finding out which smoke alarm was beeping at me like a tiny, relentless banshee, I ordered this as a replacement. It arrived quickly—faster than my patience was wearing thin—and installation was surprisingly easy. I’m no electrician, but even I managed to get it up and running without calling in reinforcements.The LED indicators are a nice touch, giving clear signals instead of the usual cryptic chirps that leave you questioning your life choices at 2 AM. It also syncs with other alarms, which is great for safety but slightly terrifying when testing them—like setting off a mini fire drill in your own home.Pros:✔ Quick and easy installation✔ Clear LED warning lights (no more mystery beeping!)✔ Interconnects with other alarms for full-home protection✔ Meets updated safety standardsCons:✖ The alarm sound is intense (which is the point, but still… it will wake the dead)✖ No option to silence minor false alarms quickly—toast lovers, bewareOverall, it’s a solid upgrade that does its job well. If only it could also detect which alarm is beeping before I lose my sanity next time!
Verified Purchaser · February 1 · ✓ Amazon Verified Purchase
★★★★★
Works great easy install
Quality product and solves two problems in one unit. If you want to make these smart it’s pretty easy to do so by adding a DC signal sensor and something like Home Assistant and your not locked into some proprietary cloud service. The install is simple and quick and the mounting plate fits snugly against the ceiling for a clean look. Simple to test for confidence it’ll work (hopefully never need to test for real).
Verified Purchaser · January 8, · ✓ Amazon Verified Purchase
★★★★★
Recommended by the pros - installs easily
I was replacing two very old BRK hard wired units, and my HVAC company owner friend highly recommended these Kidde units. These are the combo CO/Smoke units that are hard wired, with a battery backup. The only minor issue is there are no wire nuts as part of the package, but I reused the existing wire nuts from the units being replaced, plus I had many on-hand. The units installed very easily and the backing plate had all fastener options (holes) to connect to the electrical box.Note if you do have older units in place that connect with the "3rd wire", all existing units needed to be removed prior to starting to replace them. If you leave any in place, all the units will sound off during the install, which is a bit disconcerting. Kidde support confirmed that all older units need to be removed prior to installing the first one. Overall I give these a 5/5.
Verified Purchaser · December 2 · ✓ Amazon Verified Purchase
★★★★☆
watch for correct products!
Ordered 2x CUAR hardwire + battery detectors. Received 2x CUAR sealed boxes. One was indeed a model CUAR, the other was model CUDR - and is NOT hardwired. I will make these both work, but Kidde needs some QC attention.
Verified Purchaser · May 21, 20 · ✓ Amazon Verified Purchase
★★★★★
Work as advertised
Wired up easily, no issues. This was to replace 3 that were 10-12 years old and started chirping indicating they needed to be replaced. I purchased one wi-fi version to enable notifications to my phone. All of my detectors are interlinked, so if one goes off, they all sound off.
Verified Purchaser · May 26, 20 · ✓ Amazon Verified Purchase
★☆☆☆☆
Beeps in the Middle of the Night
The unit is malfunctioning after about 2.5 years. It beeps in the middle of the night as though the battery is out, but even when we install fresh batteries, the unit starts beeping again after about a week. It’s happened about five times, always in the middle of the night. I have performed all the diagnostics and now have to replace the unit. It’s been a real problem because the only way to stop the beeping is to either disconnect it or perform a test which, because the units are interconnected, wakes everyone up.
Verified Purchaser · April 27, · ✓ Amazon Verified Purchase
★★★★★
Super-fast delivery, install, etc.
Super-fast delivery, install, etc. I replaced Kidde smoke (only) detectors, with these. I didn't even have to change the mounts, and the originals were from the 1990's. I did have to wire in the new connectors, but this is super easy if you turn off the breaker and test if the hot/line wire is dead. If you are not comfortable doing so, you will need to call someone who is.
Verified Purchaser · April 26, · ✓ Amazon Verified Purchase
★★★★★
I thought it was a little expensive
Nice product comes with a ten year battery backup
Verified Purchaser · May 14, 20 · ✓ Amazon Verified Purchase
★★★★★
Great update
Meets the new code requirement of both smoke and radon
Verified Purchaser · June 14, 2 · ✓ Amazon Verified Purchase
★★★★★
works
fast and professional
Verified Purchaser · May 9, 202 · ✓ Amazon Verified Purchase
Showing 10 of 2,055 Amazon reviews.
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Frequently Asked Questions
What is the kidde 900cuar?
A hardwired interconnectable combination smoke and CO alarm. One unit warns of both fire smoke and carbon monoxide, saving a device and a spot on the ceiling while covering two of the most common home hazards.
How is it powered?
Confirm the power source on the listing - battery, plug-in with battery backup, or hardwired. Battery-backup and sealed-battery models keep working through a power outage, which is when some CO risks rise.
Where should I place it?
Follow the manufacturer manual and local codes: generally on every level and near sleeping areas, away from dead-air spots. See our CO placement guide for room-by-room guidance.
What do I do if it sounds?
Treat every alarm as real: get everyone to fresh air outside and call 911 or the fire department, then have the CO source found and fixed by a professional before returning.
Is it the same as an industrial CO monitor?
No. This is a residential early-warning alarm. Occupational settings where CO can reach IDLH levels need industrial gas-detection instruments and rescue procedures. Use the right tool for each environment.
Does it detect both smoke and CO?
Yes - a combination unit senses both smoke and carbon monoxide and signals which hazard triggered it. Confirm the sensor types (for example photoelectric smoke plus electrochemical CO) on the listing.
How long does it last?
CO sensors have a service life, typically several years, after which the unit must be replaced, not just re-batteried. Confirm the end-of-life date and replace the alarm on schedule.
How often do I test it?
Test with the button monthly and follow the manufacturer's maintenance schedule. A CO alarm you never test is a CO alarm you cannot trust.
Can it be interconnected?
Some models interconnect so one alarm triggers all. Confirm interconnect capability and compatibility on the listing if you want whole-home alerting.
Is it UL listed?
Confirm the current UL 2034 listing on the product page. A CO alarm should carry the applicable safety listing for residential use.
Does a CO alarm replace appliance maintenance?
No - it is a last-line warning. Have fuel-burning appliances, flues, and vents inspected on schedule so CO is prevented at the source, not just detected.
How do I order several?
Quantity purchasing runs through a free Amazon Business account - volume pricing, PO numbers at checkout, and tax-exempt eligibility for qualifying organizations. The bulk-ordering walkthrough is linked in our footer.