Smoke alarm fitting

[Ribosome]

Hi, I am trying to fit a smoke alarm down stairs, there is a second smoke alarm that is interconnected upstairs.

The house was built in 1994. The old alarm had two red wires linked together, a blue and black wire linked together, a single yellow wire and a green / yellow earth wire.

Now I've gone like for like with the connections on the new alarm. Both red wires into live, blue / black into neutral, yellow into interconnect and green / yellow into Earth. However when I've put the mains back on the alarm just goes off and won't stop after pressing the silence button.

The wiring seems fine. I'm assuming it's to do with the other alarm upstairs. How bad have I cocked it up?

 

[sparkymarka]

Is it the same brand of smoke detector ?

 

[Ribosome]

No it's different. I've actually sorted it now. The upstairs smoke detector was still connected and interfering with the new one. Cheers.

 

[sparkymarka]

In other words don’t mix different brands ....and if the other smokes are the original ones from 1994 they are probably past replacement ...