Hi,
My husband and I live in a three-storey townhouse with a mains-connected smoke alarm on each floor (in the landing/hallway). Just over a week ago, we got woken up at around 4am by beeping from the smoke alarms. They weren't at regular intervals (pretty random beeps), and there seemed to be a lot of time in between each beep.
It was difficult to know which smoke alarm was the problem, and since I replaced the battery in the bottom floor smoke alarm fairly recently, I replaced the batteries in the alarms on the top and middle floors hoping it would solve the problem. It didn't, and so I replaced the battery in the bottom floor alarm too, only to find that the beeping was still happening when I got back from work (just about when the central heating kicks in).
Noticing on the units (Ei141 models), they needed replacing prior to Dec 2014 anyway, and so I assumed it was just a problem with the actual units. We are tenants, and so had to go through the letting agent and the landlord's recommended contractor.
Anyhow, rather than explain the problem to the electrician, the letting agent just told him that the units need replacing, and so they were replaced 4 days after the initial beeping (last Friday). They are now Newlec NL3631 models, which seem to be pretty similar to the Ei141 units.
As you can guess, the beeping still happens in the early hours of the morning and during the day, i.e. when the heating is off. We left the heating on for the past two nights to see what would happen, and there were no beeps. I explained as such to the electrician this morning before he checked them again. He said that there was no issue with the mains (mains were checked and he replaced overheads?!), and was stumped as to why the heating would have an effect since the alarm instructions say that they are fine in temperatures above 5 deg C. I also explained to him that we've been in this house since Sept 2011 and the house has been colder in previous winters with no beeping from the smoke alarms.
Any ideas as to what the problem is?? I've heard that when batteries get cold, it can fool the alarm into thinking they're running low which might explain why the alarms beep, but as mentioned above, the house has been colder than this before. Also, I don't really want to keep the heating on every night!!
Hope you can help!! It's like slow torture!!
Amy