Customer Reviews

Kidde 900-0234 Nighthawk Carbon Monoxide Alarm, Long Life AC Powered with Battery Backup and Digital Display

5 star:		(19)
4 star:		(11)
3 star:		(0)
2 star:		(1)
1 star:		(9)

 

 

Kidde makes good CO detectors. We've had several Nighthawks for years and they've worked well (at least we think so, never had a CO problem). Our previous version was the the COPP-3 (we had a couple of experiences with the low battery chirping-- a nuisance in the middle of the night--and once, it happened again shortly after we had put a new battery in. Others have had many more problems in that regard--see reviews).

It was time to replace them. We first bought 3 Kidde KN-COPP-B Front Load Battery-Operated Carbon Monoxide Alarm with Digital Display--but ran into several problems (see my review). The biggest problem was that Amazon's stock was old (the detectors were over 2 years old) and the warranty was only for 5 years. Other downsides are that they required mounting and were only battery operated! We returned them making use of Amazon's consumer-friendly return policy.

We then bought this model. It has these great features.

1) Comes with a 7-year warranty (new feature, old had 5 years).

2) Shows the CO level continuously. It's reassuring to see the red LED showing 0!

3) Has a well designed, clearly organized printed manual (a small booklet).

4) Operates off of AC with a battery backup. (That's helpful as you have the best of both worlds!)

5) Has peak level button (this is a new feature).

6) Battery included.

A Big Downside:

A big downside is that they eliminated the plug on a cord. That was really helpful as it gives the user real flexibility in where to put the detector. In our bedroom, the only accessible plugs are beside a dresser in a corner or between bookshelves and the TV stand, meaning less air flow. With the old model, you could plug in the device and then with the cord, put the detector on the top of a bookshelf or stand. Much more convenient.

The other problem, which plagues all the CO detectors and many other products on the market, is the infuriating, hard plastic packaging. It's hard to open and I even cut myself on it. There are alternatives that are just as secure but much friendlier to the environment and the customer!

We still have a year or two left on one of our old ones, so we're keeping that. We also bought a First Alert CO615, which does have the cord, and we'll probably move that into our bedroom when the time comes. (But it has more negatives--see review!)

Set up was easy. Love the digital read-out. And I love that in 7 years the unit will tell me it's time to replace it. Nice sticker on the top to write in the date myself too.

My only complaint, if you want to call it that, is that you have to hit the button in the back to kill the sound that you hear continuously if you unplug the unit from the ac. Glad I figured that out before the first power failure or the unit would have gone on and on.

Overall, a great unit at a great price.

The alarm on this device could wake the dead. It is larger than it appears, and covers both receptacles. Installing the back-up battery isn't fast--you must unscrew a little screw to get the battery door open, and reinstall it to get the door closed again. Believe the instructions when they tell you to plug it in as soon as the battery is installed to avoid the alarm going off. I didn't time how long before the alarm sounded, but it isn't long at all based on my personal experience. I suggest you install the battery in the room where you are going to install the unit. It is reassuring to see the red zero on the displays. I have two of them, and would buy the product again.

Long-lived CO alarm requires replacement at the 7-year mark, and has an annoying tamper-resistant feature (but it can be turned off).

After learning that home carbon-monoxide sensors have a finite lifespan, I decided to replace my oldest Nighthawk (well past its "expiration" as far as I can tell), with one of this new product line that is supposed to be effective for longer.

I found a few interesting differences between this new model and my older ones. One is that while this model is rated to last 7 years, it actually has planned obsolescence-- at the 7 year mark (from 1st power-up), it begins to chirp every 15 seconds. That means in 7 years, you must replace or discard the unit. Since I doubt the sensor completely fails between 6yrs364days and 7yrs, this seems like an attempt by Kidde to ensure sales volume (or to reduce liability by picking a "safe" cut-off). I'd have been happier with the ability to either service the unit (replace the sensor rather than discard the whole), or just have a "replace unit" warning light. I'd think it better to have a unit working with diminished capability, than to have no unit at all.

There are also alarms tied to the unit receiving AC power, with the unit sounding a loud tamper-warning otherwise. Eg, once the unit has a battery in it and is plugged in, if you were to simply unplug the unit, it would sound a very loud, persistent alarm. So to move it, you have to hold down the test button for 2-seconds first, to get a 2-minute unplugged grace period before the tamper-siren sounds.

I'm not sure if this feature is aimed at consumers with small misbehaved children, or aimed at those paranoid about malicious actions, but it seems out of place in an adults-only household. Reading the manual, I did discover that this feature can be disabled (hold down the button on the back, and use a screwdriver to slide a recessed switch to a disabled position). I'm glad the "feature" can be disabled, but considering the number of reviews here that mention the tamper-alarm, this work-around seems non-obvious.

Like most recent alarm devices, this unit will beep regularly when it has a low battery (a feature not present in my oldest Nighthawk), but thankfully it does have the ability to silence that beeping (for 12 hours) by holding down the test button (since these batteries seem to always fail during the middle of the night).

The manual states that using the recommended brands of 9v batteries, this unit will run on battery-only

for 20 hours.

I haven't had any CO problems, but this unit seems like it'll do the job, but I dock 1-star for overly noisy warnings and planned obsolescence.

Both 2 of these to replace my 7-year-old Kidde CO detectors of a similar model, one per floor. They plug into any wall outet. I like the battery-backup and the digital CO level display. If you press a button, you can see "peak" CO level since the last reset. Am using these peak level readings to try to track down occasional very low levels of CO that are too low to be dangerous or trigger any alarm. I am pleased with these CO detectors. My only complaint is that I wish I could see the instantaneous low level CO readings [but such pro CO detectors normally cost much more].

One important point. There is something you have to do to prevent the unit from beeping every minute on battery backup if the AC power goes out. Follow the instructions to do that and you will like this unit much better as a result.

After owning the other Kidde CO detector with digital display (Part Number 900-0076 Model KN-COPP-3), I was about to buy another one until I found this Kidde 900-0234 for a much lower total price (as compared to Lowes or Costco) here on Amazon shipped to my door. The old one lasted about 7 years without any problems then gave me an error code and stopped working. Looking into it, these Kidde CO detectors apparently have a shelf life of 7 years and that was true for my case. There is not much difference between the two; this one is a plug in and the other has a cord with a small plug in transformer. Both have the same features and work the same.

One thing people should be careful of is the shelf-life of these, luckily mine had only a 2 month old build date stamp on the back. The 7-year timer is suppose to start the count down after initial plug-in, but Kidde seems concerned about sensitivity as these age, probably for liability reasons. Seems like most people would want the newest one for best sensitivity and longest life.

So far so good after one day of use.

This detector is an update of a plug-in carbon monoxide detector that Kidde has been manufacturing for some time, and that I've owned for about a decade. The design is distinguished by a continuous, easily-readable display of the carbon monoxide level, which is normally 0 ppm in our house. The updates now include a battery backup, a peak-level memory, and an anti-tampering feature.

The anti-tampering feature is a good thing to have, but the manual is not very helpful in explaining it. It is based on a little electrical switch on the back of the detector that is pushed in when the detector is correctly installed into the wall outlet. If the detector slips out or is removed from the wall outlet, a loud anti-tampering alarm sounds that appears to be indistinguishable from the alarm when carbon monoxide is present.

This anti-tampering switch depends on a reliable, tight fit of the detector into the electrical socket. I first installed the detector into a loose-fitting socket from the original, 1960 construction of my house. The consequence was an anti-tampering alarm in the middle of the night, when the detector somehow worked itself loose from the socket. I needed to replace that wall outlet to get the detector to work properly. This wasn't a bad thing, since a reliable electrical connection to a carbon monoxide detector is pretty important.

On balance, this is a very well designed detector, and the engineers at Kidde were clearly concerned about the reliability of its installation. In my case, installing the detector required that I change the electrical outlet socket. I don't know whether this problem is a common one. The manual from Kidde doesn't address this possibility.

I had a scare with CO in January which led me to the purchase of a new furnace and now CO Alarm systems. I invested so much in my new furnace I was not about to not arm myself with the best CO detectors around.

Did my homework and found this to be the best on the market. The price is not cheap (but you do get what you pay for) and the benefits outweigh the one time expense for at least 7 years. I purchased 2 for the main floor and one for the basement. They all read "0" for a clean feel of NO carbon monoxide readings in home home. Huge relief after my scare earlier this year.

The systems are very hard to open so caution when you do - they are in those sharp plastic tight containers. I have heard of others cutting themselves when trying to open them. Each container is provided with a battery - nice touch. You'll want to get near the outlet you plan on using for your system. Once you put your battery in, the system will SCREAM so loudly it'll pierce your ears. Place it in your outlet and it'll stop and start to 'read' to function. You will need a screw driver to open the contraption to put your battery in - child proof I suppose.

I hear if your battery starts to chirp and is low on usage, your system will sound off but there is a button on your system to "turn off the noise" for up to 12 hours to give you time to replace your battery.

They provide you with stickers to place on the top of each system to write in the month/year of your installation as your detectors are good for up to 7 years and at that point will need to be replaced.

Worth it. For the peace of mind in knowing we're safe. I'm OK with this and nothing is free in this world. Why wouldn't I want new systems in 7 years? I think I can handle that.

Word of caution if you call KIDDE tech support to get answers to your questions, they have very poor customer service and if you rely on the manual, you should be OK. I did provide feedback to their PR dept and asked to be contacted only to be diverted BACK to technical support. I suppose no one wanted to be bothered? Specifics on this were posted on YELP.

My experience with this purchase from Amazon was great. I ordered it one day to get it literally 2 days later. Great turn around.

I have had this unit in our bedroom for over 6 months with no issues. No false alarms and no backup batter issues, it just works or at least the display tells me so. I do like the display on these units rather then just a status light like other lower priced models. If you are looking for a higher quality carbon monoxide detector then I would sure take a look at this unit. I have had other Kidde Nighthawks with no problems as well. Just remember that after a number of years all detectors are no longer good and need to be replaced.

Product arrived ready to use, right out of the box. I only had to insert the battery and plug it into the wall. Very easy for anyone to use. Digital readout shows CO levels at all times (mine has always said "0"), plus you can scroll through to see the highest recorded readings, average readings, etc. The CO alarm is very affordable, provides peace-of-mind and is an overall great value for the price. Highly recommended.