No power to mains-connected smoke alarms

hibby

I moved into a house in May, and it has 3 ceiling-mounted baseplates for mains-connected smoke alarms. One in the kitchen, with an EI164 heat alarm; one inside the front door, with just a bare baseplate, and one on the landing, with an EI161 ionisation smoke detector.

None of them is working. They are completely dead: no lights; test button is unresponsive; zero voltage measured at the base-plate connection.

I've checked the fuse-board and all the switches are set to "ON".

I don't see anything that looks like a wall-mounted central control unit.

Is there any possibility they are linked to the house alarm? I had to remove the fuse from the house alarm control panel after I moved in, because I don't have the code for the alarm.

Any other suggestions? I'm not comfortable about having no working smoke detection in the house, especially at Christmas with a tree in the house.

CountyHurler

hibby wrote: »

IIs there any possibility they are linked to the house alarm? I had to remove the fuse from the house alarm control panel after I moved in, because I don't have the code for the alarm.

I've googled around those detectors and it seems that they have battery backup, so maybe you could get them up and running temporarily by replacing the on board batteries in them? Seems like they take 9V batteries.. Is this right?

Have you measured the voltage on all devices and there is no voltage going to any of them?

hibby

You are correct that they have battery backup. The battery is supposed to last for 6 months on standby with no mains connection. However I need to replace the 3 alarm units anyway - two are out of date and one is missing. So it's more a question of why the electrical connection isn't working.

I checked two of them and found no voltage. I haven't checked the third one (upstairs landing) yet.

CountyHurler

I would think that if all three are not connected to the mains, and all MCBs are on then I can think of only a few possibilities...

i) The wiring was done for each alarm but was never actually wired to the consumer unit? (Can you confirm that they were they ever actually working off the mains)
ii) They were wired and working successfully but the wiring was disconnected from the consumer unit for some reason..
iii) They are somehow wired in series with that fire alarm that you are speaking about, and you pulling the fuse on this also pulls the power to the other boxes... (could you temporarily plug the fuse back in to the fire alarm and have somebody check if the lights come on on the alarms).

braddun

flick the breaker a few times,put in new batteries,if its a rental call the landlord


pull them down and take photos of wiring with your phone and post here

hibby

Thanks for all the suggestions guys. I'll try to upload some photos tomorrow.

No landlord to call - I bought the house so it's my problem to solve.

I can't confirm that they were ever working, and I have no way to find out. (I wasn't even able to get the code for the alarm from the previous owners.)

One thing I won't be doing is putting the fuse back into the house alarm control panel (it's an intruder alarm, not a fire alarm). As soon as I reconnect the fuse the alarm will sound, and it's absolutely deafening!

Stoner

is there a zone list with your intruder alarm? this might list fire detectors on it.
take a photo of the unit with its model number and also with the lid open. It might be on the intruder alarm, although as far as I know the intruder alarm ones don't have a battery in them, they use the battery in the intruder alarm panel as the back up, however there could easily be a model on the alarm with batteries that I've never seen.

You'd spot the intruder alarm cable, it will be the multi-core white or brown cable usually.
220Vac power cables would usually have a grey outer colour

hibby

This time with photos (see attachments).

Each of the mounting plates has a block with 3 terminals: L, IC and N (live, interconnection and neutral). In each of them the IC terminal is not used.

There is no "alarm" type wire going to the mounting plates, only electric cable.

I've checked all 3 mounting plates and found no voltage at any of them.

The ionisation smoke alarm has a space for a 9V battery but the battery is missing.

The heat alarm has a lithium battery but it's not replaceable.

hibby

I'm including a photo of the alarm control box and another with the box open as requested. However I am pretty sure now that there is no connection between the two systems.

Robbie.G

hibby wrote: »

I'm including a photo of the alarm control box and another with the box open as requested. However I am pretty sure now that there is no connection between the two systems.

The smoke alarms are probably connected on the same mcb as the burglar alarm.
With the alarm panel cover open take out the internal fuse and then turn on the mcb and see if that does it

hibby

Hi Robbie,

It's a good suggestion but all the MCBs are in the "ON" position (see photo).

I disconnected the alarm by removing the internal fuse.

Dara

dingding

Hi OP

I would suggest that you get a couple of ordinary smoke alarms. They are not that expensive so you have some protection. Would these have been looped from a lighting circuit and disconnected at one of the ceiling roses.