My smoke detectors are going off almost on schedule daily. 1 beep around 2pm and 3 beeps a little after 10pm. It's the same amount of beeps and same time daily. PLEASE! HELP!
I haven't run into your situation and I don't know your brand or model. They may just need interfering dust blown out of them. But, basic detectors only beep by themselves if the battery needs replacing. I suggest taking down a (or more) detector down and find out what the brand and model is, so you can possibly find an Instruction or Owner's Manual to decipher the beeps.
It may turn out that you have Dual Detectors that also monitor Carbon Monoxide and the beeps are signaling replacement of the entire unit (they're quite short-lived devices). Or, they may be actually picking up something when the water heater, furnace or clothes dryer run. Call in a Professional.
Finally, you may be dealing with hard-wired detectors that just have a backup battery, which may need replacing at some or all of the units. But, these too may be signaling replacement of the units or an electrical problem. Some setups use a Transformer in a low-voltage arrangement and that Transformer may be cutting out as it heats up and needs replacement to stop the beeping.