E156LH - False Alarms at Night

Hi,

My father who currently has just had major surgery has serious problems with his Ei156LH smoke alarm.

The layout of the house is that there is an Ei156LH downstairs and an E151LH upstairs. From what I can see the upstairs works fine.

The downstairs alarm has had a habit of going off randomly, mostly in the evening and overnight but never during the day. The problem is that him getting up to turn it off is hard for him to reach. 

There is no burning or smoke anywhere and the upstairs alarm whilst ringing, appears to be working fine and isn't the source of the false alarms.

I've cleaned the Ei156LH out as well as I can bearing in mind it's a sealed unit, and I've also tried things like turning radiators off overnight, ensuring all lights are off, leaving certain doors open to try and flow the air as best as possible to help, leaving certain doors closed, and nothing seems to really make much of a difference.

The alarms show that they need to be replaced by October 2021, so obviously it makes you wonder if the Ei156LH has come to the end of it's life a little bit earlier than planned because it is behaving erratically. 

Is there anything else I can check as to what is causing this? The only thing I can think of is that my father is on some quite intensive drugs and he uses a comode downstairs, now I know that it sounds stupid, but it's the only change in the house in the past few weeks since this issue began so it makes you wonder.

Obviously at the moment getting a repair person out and getting new alarms fitted is slightly awkward at this time, so appreciate any help you can give to try and get through the next little while with these alarms before we can get new ones and the new faceplates fitted. 

Thanks for any help you can give.

James