See recent reviews by others (especially Robert Oppenheim) as well... We just got two of the redesigned ones and indeed they have dropped the remote control feature (good thing) and that would make them deserving of 4 stars, however, they also changed the Peak Level recording, automatically deleting it every 24 hours--that's a bad thing for several reasons and leaves my rating at 3 stars:
1) The peak level resetting should be under user control.
2) One wants to know if, say, during the past week, there was an excessively high reading. Given how it now works, you cannot find that out!
A 24-hour automatic clearing of a bad reading hides potentially dangerous, even lethal situations. (Unless one becomes obsessive about checking this every day!) In this day and age, they really should have a small memory and track days and peak levels!
Here are some other updates--and First Alert deserves credit for listening to some of the critiques.
1) The manual, well it is really a pamphlet, is more readable now.
2) The warranty has been upped to 7 years.
3) They greatly improved the packaging.
Alas, the way the unit is designed means it still wobbles on a nightstand or bureau; the battery cover still doesn't work very well; the CO level still shows up only if one presses the button (and that's a tricky press); the battery symbol still suggests that one is on battery power--they really need a dual indicator for that. In fact, it would be better if you had to press to get the battery level, but that the current CO level would always be displayed. (It's now the reverse.)
Unfortunately, there's another problem. The darn thing glows in the dark and lights up an entire room. It makes it nearly impossible to keep it in a bedroom. We miss the comfortable soft red light 0 of our old Kidde model immensely (but their newer ones seem to have BRIGHT RED lights now).
I would have been happy to give this 4 stars, especially given the various improvements, had they not adopted the 24-hour peak level reset. Oh, well.
I have updated my rating and review to include CONSUMER REPORTS' FINDINGS. It was top rated by them. That initially improved my rating, upping it to four stars. Well, we're now DROPPING it back down one. We discovered that the remote control "feature" (which we had viewed as a gimmick in any case) is not one! Turns out, that if we press the Mute button on our remotes (just press, not even holding them down), the darn CO alarm goes off! The remote test operation is only supposed to happen if you hold down the volume or channel button for FIVE seconds.
We bought this to supplement our Kidde Nighthawk CO detectors, the 900-0234 curved model with a 7-year warranty (we didn't want to put all our eggs in one basket!). The First Alert looks to be a fine CO detector.
Here are some positives:
1) It has the plug on a wire, so that you can put the detector somewhere other than right in the outlet. That's helpful as outlets can have other adapters in them making it hard to plug it in or be behind something rendering the CO detection harder.
2) It can be tested or silenced with a remote (hold down the volume or channel button for 5 seconds) (our Tivo remote worked!). (Some of their other products with the remote features have received critical reviews as regular remote operation has set them off!)
3) Operates on AC with a battery backup (2 AAs)
4) Batteries ARE included!!
5) A biggie! Consumer Reports rated this much higher than the Kidde brands. It's better at detecting low levels of CO.
Here are several negatives:
1) 5-year warranty unlike the Kidde's 7-year. [This has apparently been upped to 7 now, but check with the company.)
2) A "manual" that's a huge, cumbersome, folded sheet, with small print that's blurry and hard to read. They should supply a magnifying glass with it! This is a major concern as one needs to refer to the text for installation, for operation, to determine what to do under certain conditions, etc. [This also supposedly has been improved.]
3) Yes, one can park the detector on a bookshelf (with the cord going to the outlet), but the detector itself wobbles! The previous Kidde CO detector Nighthawk model--the COPP-3 -- has the plug on a cord feature, along with a nifty slide out stand that makes it stable. (We had good luck with that model, but many did not. Plus, it's an older model, with only a 5-year warranty which is why we went for the 900-0234).
4) The CO level only shows up if one presses a button. It's a cool blue light, but unlike the Nighthawk's red LED that shows you the current CO level at all times (a reassuring 0), this displays a blank screen with a recessed green light. For some, it could be a plus as it would be less intrusive especially as the Kidde's red LED seems to be much brighter on their latest model.
5) The detector displays a battery icon when it's plugged into AC and the battery is installed! That's unnerving as it makes it look as if it's running on the battery! Very odd design choice, as in most of the electronic world, that's an indication that you are running on battery power and no longer on AC (take any laptop, e.g.).
6) The test alarm didn't seem as loud as the Kidde's.
7) Battery cover is the front of the device, which the manual didn't explain or illustrate, and it doesn't shut well--or rather, it's awkward and you feel as if you're about to break the lightweight plastic parts.
8) One other issue, 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!
In comparing the two (Kidde Nighthawk 900-0234 and the First Alert CO615), the advantage on first glance clearly goes to the Kidde. It just seems a more professional, better designed, and better thought out product. Part of that is because we're used to the Kidde design and like the red LED, but it also seems more solid (the First Alert has the seemingly fragile/flimsy cover), and has a higher quality, usable manual--it's a real booklet that's more readable and better organized (it also has a bigger font than FA's, but still could be larger).
UPDATE--OTOH, I'm a believer in most of what CR does--and the testing on these--and the user reports here and on the web--suggest that it is the better detector. And, after all, that's what one buys these things for! However, we're not going to be able to use this in our bedroom as the Mute button sets off the alarm!