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Mains smoke / heat alarms questions

Discussion in 'Electrics UK' started by ey143, 10 Jul 2021.

  1. ey143

    ey143

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    We're at the first fix stage for wiring up mains smoke alarms and heat detectors as part of a large renovation of a sizable house. Pretty much every room will have a detector (our choice).

    1. Whichever interlinked smoke / heat alarm we go for, am I right in thinking that if one goes off, then they all go off? If so, then does deactivating the alarm in one room also stop the sounder in all other rooms?

    2. Is it a bad idea to have a mains smoke alarm in each room like I have done for the purpose of false alarms etc? I suppose most false alarms are due to the olden days when wrong detectors were fitted near or in the kitchen and burnt toast scenarios occurred and as long as heat detectors are used, then low probability of them occurring now?

    3. What products can do both Co2 and smoke or heat?

    4. Can any provide an alarm notification to a smart phone e.g. I guess Nest and Hive probably do but any more?

    5. With approx. 15 in the house, will these need to be replaced at some point or are they good for 20 off years. I recall that the cheapo ones need replacing every 10Y or so.

    Thanks.
     
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  3. Harry Bloomfield

    Harry Bloomfield

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    Yes, that is the whole point of them being interlinked. They are normally all fed from a single mains supply cable.
     
  4. Taylortwocities

    Taylortwocities

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    2. Most the point of a linked alarm inside a room provides 2 purposes.
    It detects the presence of smoke etc in the room and sets off the other alarms.
    It alerts everyone else in the property to the fact.
    You have to make a risk assessment for each room as to the possibility of there being a fire/smoke etc issue. Never seen a smoke alarm in a bathroom for example. In most houses alarms on the landing will provide sufficient sound levels to alert the sleeping MIL.

    3. You don’t get CO2 alarms. You need an alarm that detects the presence of Carbon MONOXIDE (CO). A CO alarm is needed where CO could occur. Usually where there is a gas appliance. Boiler/gas fire etc. You don’t need a CO alarm if your house is all electric.

    You can get combo smoke/heat/CO alarms. Eg. https://www.tlc-direct.co.uk/Products/EI3028.html
    L
    ook at the whole Aico range. They are very good. Read this
    https://www.aico.co.uk/blogs/check-out-our-guide-to-alarm-types/
    All of your questions can be answered here https://www.aico.co.uk/technical-support/alarm-selector/
    Use the alarm selector and FAQ options.

    4. on the Aico site

    5. Most smoke alarms have a lifespan of eight to 10 years. The slarms contain a small radioactive component that decays over time. Hardwired mains alarms have a secondary battery. In some the batteries are replaceable, in others there is a fixed rechargeable lithium cell that is designed to last as long as the alarm does.

    Hope this helps.
     
  5. crystal ball

    crystal ball

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    I fitted Nest alarms in a holiday let, it alerts the owners if anything is amiss and they send their locally based caretaker round to investigate, not cheap though especially when the shower tray overflowed and soaked one
     
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  6. Taylortwocities

    Taylortwocities

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    How deep was the water then! ?
     
  7. ey143

    ey143

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    Thanks for the responses. My builder inspector initially said that if we had smoke alarms in each room then we could escape having to put FD30 doors on all enclosed rooms as part of our renovation which is what we did. Roll forward, as I renovation get delayed, he couldn't remember saying that so now we have first fixed alarm cables to each bedroom and also need to put FD30 doors.

    If smoke alarms need replacement every 10 years or so because of the radio active decay, can I then just put heat alarms in the rooms where there is no risk of co2 e.g. in the bedroom and not have a need to replace them in 10 years, which will be quite costly for me i.e. over £1500 for circa 15 alarms in the whole house?
     
  8. crystal ball

    crystal ball

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    The alarm was directly under the bathroom, the blame lies with guests with long hair not unblocking the plughole, not a problem I have personally
     
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  9. Taylortwocities

    Taylortwocities

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    You need an expert to advise you if alarms are needed in all rooms if FD30 doors are provided.
    What sort of property is this? Do domestic premises need fire doors?

    im not qualified to advise. As before, call Aico.

    PS
    CO alarms also have a lifetime of 8-10 years. So that’s not your get out of jail card. You might just be able to put a linked sounder in rooms that don’t need detection per se. Or a sound bomb in corridors. Again, you need an expert todo a risk assessment.
     
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  11. flameport

    flameport

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    All smoke, heat and CO alarms need to be replaced after 10 years. That's how long they are designed to work for. After that they may still work, but the components in them will have degraded and they will be full of dust.

    Radioactive decay is unrelated, the radioactive material used in that type of detector takes centuries to decay. Radioactive types are obsolete and shouldn't be used on a new installation. They are the ones that are ultra sensitive to invisible particles, including the ones created by cooking, and created false alarms all the time.

    For new installs, it's optical smoke alarms for most rooms, heat alarm for a kitchen, and CO alarm for locations that have fuel burning appliances.

    If you get the Aico 3000 series, they have rechargeable batteries built in, so nothing to replace for 10 years. When replacement is required, it's just a matter of removing the old one from the backplate and attaching the new one, takes a few seconds with no rewiring required.
    For installs with multiple alarms, a remote control switch is available which can test them without going to each alarm separately, silence all except the one that caused the alarm, or silence all of them.
    They are also made by a company which specialises in fire and gas detection, and has been making them for decades.

    Or pay more than double for the Nest hipster efforts, which are desperately unlikely to be supported in 10 years time, may or may not work as described and have the feature of being able to update their own firmware over the Internet and cease functioning due to that update failing. Or when Google decides that a new version is to be foisted upon the world and the old ones are EOL.
     
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  12. SimonH2

    SimonH2

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    Yes, the Aico 3000 range are very nice units - but the radio modules (for use when you can't hardwire) are as much as the alarm units. But ... the interlinking functionality when hardwired is less than when using radio. Specifically, if you have a multi-mode unit (e.g. heat and CO), over radio the other alarms can repeat the different alarm signals, while hardwired ones simply use the same tone for all alarm types.

    You missed out, half the functionality required a working internet and wifi network - both of which we know are totally reliable and lever fail !
    And of course we have historical evidence that Google has no problem screwing over anyone in search of a bit more dosh. Ask the owner of any Revolv hub ... er Revolv doorstop. Google bought the company that did the Revolv home automation kit - and then shut down the servers without which the Revolv stuff didn't work.
     
  13. JohnW2

    JohnW2

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    True, provided that replacement alarms which fit the same backplate are available 10 years down the road.

    Kind Rewards, John
     
  14. Risteard

    Risteard

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    Ei keep them consistent between models.
     
  15. JohnW2

    JohnW2

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    They have so far. Someone might one day come to be in charge at Ei who realises that what is clearly a great advantage to buyers/users is not necessarily a good commercial strategy :)
     
  16. SimonH2

    SimonH2

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    True, but there's little value in the bases which have nothing but a connector in them. And Aico have said (IIRC) that it's now policy to stick to the one universal base.

    Besides, there's a strong commercial argunent against changing the base ...
    If the user can just unplug the old alarm and plug in a new one then they are incentivised to stick to the same brand. Once they have the inconvenience and potentially cost (paying someone to do it) of changing the base then they can easily switch brands. So making it easy to stick with your brand makes sense.
     
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  17. Risteard

    Risteard

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    I doubt it, because it would probably cause a backlash. They might be Irish - but they're not stupid. They're market leaders for a reason.
     
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