Intermittent alarm from smoke detector

[Guest Tom Saul]

We have three mains powered EI161 smoke detectors. Very occasionally (less than once a year) the one in our bedroom has given a very short (about two seconds) alarm noise in the middle of the night. It then stops and nothing else happens. Last night it did this three times, the second about 5 minutes after the first and the third about an hour later. Also one of the other alarms in the house gave a similar short alarm noise immediately before the one in our bedroom. Any ideas please?

[Safelincs]

Hi Tom

Just spoke with Ei Electronics. They reckon that it could be dust or spider webs on the circuit board and recommend that you first blow it out and then vacuum it out. The blowing out of the smoke alarm can be done with a hairdryer on the cold setting.

How old is the alarm?

Harry

[Guest Tom Saul]

Thank you Harry. The alarms are about 7 years old. They were installed by the builder when the house was new.

[Safelincs]

Did the cleaning do the trick? If not we can speak with Ei and ask for help and possibly replacement.

[Guest Tom Saul]

It has been quiet since, but it always has been a very intermitent fault. I will clean it more often in future thank you.

[Guest Craig]

Hi,

I've totally had the same problem - I've recently moved into my first property :) and have had a Carbon Monoxide Alarm (one of the Honeywell H450EN types - older model estimated at 2009? as it is good until 2016) very near to what appears to be (it is definitely an Ei) and Ei141 or Ei161RC Smoke Alarm. Both are located approximately 4-5 metres away from my bathroom, and about 1-2m from my door (which leads onto a hallway) and next to the boiler cupboard.

Occasionally in the four to five months I've been in the property (and I've only ever noticed this at weekends or during the evening as I am at work during the day) I have had a quick maybe 1-2 second chirp out of it and then nothing (it never happens more than 3-4 times in a day). I am figuring that it is not the CO Alarm (as the warning light did not flicker and have now moved that into my bedroom to isolate it from the smoke alarm). Last night I had a chirp at around 2.00am and then a couple at around 3.00am (I now know it has a hush button which is nice) which is the first time it has happened whilst I've been in bed. Is this consistent with this type of alarm? Is there any guidance to cleaning these (there was no instruction manual provided when I moved into the house). The alarm has a replace by August 2016 sticker on it (along with all of the others in the development) and has a reference in my fuse box, so I know it is mains fed and I don't think it is an age of the product issue (on that basis).

Thanks in advance for any advice.

[Safelincs]

Hi Craig

Assuming that it is indeed the smoke alarm that is causing the chirp there are two potential causes for the nightly chirp:

If it is an Ei141 model the alarm has an alkaline backup battery. This battery will last about a year or two. Eventually its power supply will start dropping and when the battery is getting colder, its power supply will be at its weakest, triggering a low battery warning chirp. If that is the case, a replacement of the battery will help. There is a video showing you how to replace the battery of an Ei141.

If it is the Ei161, which contains a rechargeable lithium backup battery, this type of drop in power supply by the backup battery should not happen. In this case I would check the date of the smoke alarm and if it is older than ten years you should replace the alarm. You can buy genuine Ei replacement heads, called easichange, which do not require electricians for an exchange of the alarm.

Harry

[Guest Craig]

Hi Harry,

Thanks for the advice. I just looked in the fusebox and when I saw a sticker marked against one of the switches as Fire Alarm figured that it was totally mains powered (as I hadn't seen the slot for putting a screwdriver in). I will definitely check this out, and think I must have the Ei141 model as every model in the development has approximately the same end date which is about 3 years away, so I'm figuring that there it isn't an age issue (the development was built in 2003/2004 though and I don't know the history of the alarms so it may be a possibility). Is there any identifying markings on the Ei141 and Ei161 that I could use to figure out which one it is?

I am figuring dirt may be an issue as well (as the flat wasn't that clean when I moved in). It has ionisation on it, and from the Ei website looks like a Ei141 or Ei161.

I'm going to call Honeywell re: the CO alarm anyway but I am figuring that it is not that on the basis that the "alarm" light did not flash (my alarm is old enough though that it doesn't have a fault light), it doesn't flash when I have my heating on (admittedly I think downstairs had their heating on around 2-3am this morning) and I recently had the boiler serviced by British Gas, and I also have the oven off (so I cannot think of any other CO source).

Thanks again,

Craig

[Safelincs]

Hi Criag

If you follow the video about the removal of the battery you will see the part number on the back of the smoke alarm and the replacement date on the side of the head. If it is the ionisation model, dust and dirt should not be so much of an issue. However, if it is the optical smoke alarm version than dust can cause false alarms and you could try vacuuming the smoke alarm head. However, you only have experienced the odd chirp, which sounds more like a battery issue.

Re the CO alarm: Try moving it away from the smoke alarms so that you can determine which alarm makes the noise. Honeywell will not be able to help you to determine which alarm is sounding. Try changing the battery in the Honeywell alarm to exclude the possibility of a low battery warning. The Honeywell alarm has a 7 year life, so you also need to check the replacement date.

Harry

[Guest Craig]

Hi Harry,

Thanks again for all of the advice. I will post back here once I have this resolved (just in case others can benefit), I was just curious as it sounded very similar to Tom's problem. I have since found the instruction manual that came with it (but it is just a generic one that refers to both the Ei141 and Ei161 so I'm going to definitely need to disconnect it and take the front off). I wouldn't be surprised if dust were an issue as well as the flat wasn't particularly clean when I moved in and I didn't think to clean the smoke alarm but I think it will be a battery issue from what you say (especially with the cold weather coming in).

Re: the CO Alarm - thanks and noted. Where the replacement date isn't until August 2016, I don't think it is the battery and I didn't think they made just the odd chirp with a false alarm (which was the only reason I was going to phone Honeywell - to find out - I figured it would be at least 10-20 seconds). I now have it in my bedroom (next to the wall adjacent to the boiler - on the other-side of the wall) so hopefully if it does happen again I will be able to figure out which Alarm it was.

Thanks,

Craig

[Guest Craig]

Hi Harry,

Apologies for not posting back sooner on this (I've had a busy couple of weeks), I am just confirming that it was an Ei141, and I have cleaned it and replaced the battery and so far apart from one odd chirp (the alarm is located very near to a halogen spot light that had been on for a while which I think may have tripped it due to the heat given off) I have not had any issues.

Thanks again for all of the advice and have a good New Year.

Thanks,

Craig

[Guest Alarmed of Marple.]

Hi Harry,

I've just used the hoover and hair drier on my Ei141 after it was going off at random times.

A big web blew out at first and after re fixing it there has been no alarms as yet.....thank you for the advice.

ps. I was a few seconds from buying a new alarm !  

Cheers ,

Ian.

 

[Tom Sutton]

I had the same problem some weeks ago and it worked for me.

[Guest All New]

All new fire alarms that have been bought still go off , they have been replaced 3 times now , thinking they were faulty , moved twice from the position at top of landing & still they go off randomly , we have to have them as its a holiday let & people are complaining { this has cost a fortune in fire alarms } 

I have dusted , hoovered , hair dried , moved position , replaced battieris often & check all fire alarms regular & change batteries . 

Frustrated 

Thank you Su 

[AnthonyB]

Which make of alarm, it sounds bizarre! You don't have smoke detectors where they could be affected by cooking, e.g. open plan to landing or doors open.

[green-foam]

On 02/07/2021 at 11:11, Guest All New said:

 its a holiday let & people are complaining

 

What exactly are people complaining of? it is just that often on this forum people will say the smoke alarm is beeping and that they have changed batteries, vacuumed them all to no avail, only to find it is NOT the smoke alarm in question  beeping but another smoke alarm that is sitting in a drawer or on top of a kitchen cupboard that has been "forgotten about"

Over the years I have personally been to several premises where the customer says the XYZ is beeping and I know full well it isn't because it has no buzzer to beep with and sure enough I found an old smoke alarm in an "unusual" place. 

As you have changed your smoke alarms 3 times and it is still a problem I do not see how they can be the cause, I suggest that this is the case in your situation, have you also looked in the loft?

[Guest MrsD]

Hi so today I have had the fire alarm false alarm 3 times. I have read the comments on this post which is really helpful, I have cleaned it out with a hoover and a fly fell out to. The only thing is the light is still flashing there was a malfunction. Green light and every 40 secs a 2 red flashes. How do i reset that or does that indicate there is still a problem?

It is a new build new home so only installed this year.

[Guest Shelley]

I’ve had my EI alarms for about two years. Last week all four of them went off but I was able to stop them pretty quick. But tonight they all went off again and it took me a good 20 minutes to stop them can someone help with why the alarms keep going off when there is no fire.

 

thank you.

[green-foam]

 

Confirming some facts:

Which model are your smoke alarms?

When were the batteries last changed?

Did you look around all of the smoke alarms when they activated?

Were there any visible signs or smells of anything unusual?

How did you try to stop them?

Is this only the second time you have had a false alarm?

Did you time how long they sounded for?  as going off twice in two weeks is not

On 01/10/2022 at 23:56, Guest Shelley said:

with why the alarms keep going off

Was anything happening outside the property? Builders, large delivery lorry, bonfire?

What time of day (Roughly) were the activations?

Were any windows open?

Have they been silent since?

Do you test them on a regular basis?

Only asking to establish some facts.