Would it reflect some of the heat away from the house?
Most of my advice is to replace it because you don't want even a hint of questionability about its functionality. DON'T bother trying to clean it-you could never be confident of it, and the protection of your home is way more important than the few dollars for a new detector. An interesting test would be to take that one down and swap it with one in your house that is far away enough that you are confident it isn't in the same environment. If it continues to alarm in the new location, it is failing and needs to be replaced. If the other detector alarms in that same location, you may have an actual problem in that room.
Usually a low battery condition will trigger the alarm which will emit a single beep every certain period of time (1 to 2 minutes), just to let you know of the condition, whereas the beeping for presence of carbon monoxide is uninterrupted and louder, and will continue for as long as the carbon monoxide is present, until the unit is reset or until it runs out of battery. (changing the batteries as soon as needed is the best decision you can make, your life could depend on it)
Buy a carbon monoxide detector or two or three. I think you might even be able to gets ones which are combined with smoke alarms. I know someone who bought one - the minute he got it back into the flat it went off! His landlord swore there was nothing wrong with the boiler! Symptoms include nausia and drowsiness but to be honest, if a problem starts overnight when you are asleep you may just not notice. That's where the carbon monoxide alarm will give you peace of mind. Why don't you pop along to your local fire station as well, and see if they will come out and do an audit on your house. I know ours visit properties and I believe it's a free service. They'd rather help people prevent problems than have to visit tragedies.
Yes you can, check out Por-a-mold on Dick Blick's site. Also some local art supplies stores carry both silicon mold kits clear resins. Expect a huge mess, but you can do it.
Carbon monoxide (CO) alarm is triggered to sound, if it detects the presence of the carbon monoxide (CO) gas, a colorless and odorless compound produced by incomplete combustion, in order to prevent carbon monoxide poisoning. CO detectors detect and warn people about dangerous CO buildup caused, for example, by a malfunctioning fuel-burning device. In the home, some common sources of CO include open flames, space heaters, water heaters, blocked chimneys or running a car inside a garage. While a Low battery alarm is triggered to sound, if the circuit detects that a battery power supply falls below the specified rating to run the detector device. If your device have both the alarm you must distinguished the tone of Carbon monoxide alarm to the tone of Low battery alarm. Usually they are of different tones to differentiate them from one another. In your case maybe the device had detected the presence of CO gas while in its position and triggered its alarm. But when you remove it from its place the CO gas had fade and blow away to the air and stop beeping. Thinking that it is a low battery you replaced it without testing the battery if it is really a low batt. All gas detector has a Test Button, the test button on a CO alarm only tests the battery and circuitry not the CO gas sensor.
