What is this and why did it wake us all up screaming at stupid o clock this morning?

[Frequency]

It was beeping like some type of alarm for around 10 minutes. It wasn't as loud as the fire alarm but it was a similar type of beep and loud enough to wake us all up.

It's on the ceiling next to the loft hatch. We've lived here 6 years and always thought it was an air vent until it started screaming at us this morning. There are no lights on it and no branding.

I've tried Google image search which told me it was either a headlamp washer, a light switch, or part of a Boeing 737. Searching Google for "beeping white box on the ceiling" suggests it is a Cisco device, which it is not.

What type of alarm is it and is it alerting us to anything important? Do we need to evacuate the house or start getting ready for a zombie apocalypse or alien invasion?

Smoke alarm with a dying (back up) battery is my guess.

Oooo errrr…….

The only alarms I’m aware of other than smoke alarms are carbon monoxide ones 🤷‍♀️

Carbon monoxide sensor? Though they’re usually near the boiler or gas fire

Our carbon monoxide sensor is above the boiler. The fire alarms are on the stairs. We rent from a HA and whenever they come out to check the smoke alarms and carbon monoxide alarm they never look at this thing.

I'm not sure if I need to phone them or not now it's stopped. It wasn't the intermittent beeping smoke alarms do when they're running out of batteries, it was constant and loud.

You need someone from air traffic control

I'd pry the cover off with a large screwdriver, if it were me, and take a look inside. You can usually find a make and serial number somewhere, which allow you to do a Google search and figure out what it is.

How big is it? It looks almost the size of the loft hatch in that photo, way too large for domestic alarms.

Its a zombie alarm - trust me, they’re living in your loft!!!

Slightly smaller than the loft hatch but, yeah, it is bigger than any domestic alarm I have ever seen.

@cheezncrackers I was going to that this morning but by the time we worked out where it was coming from and fetched the step ladders it stopped. I'm not sure I want to risk setting it off again yet. I'm starting work in an hour and don't want to have to sit about waiting for the emergency repair man all night.

Looks like aircon - can you put your head in the loft hatch and see if the main unit is in the loft?

Do you live in an old house, possibly in a radon area? That looks like a positive ventilation system to me. There will be a fan in the loft if so. Dunno why it would be beeping though - fan not working?

It's a loft vent https://www.diynot.com/diy/threads/loft-vent-letting-cold-air-in.560078/

Ah, there is "thing" in the loft. I have questioned the HA about it before because sometimes there is a wall of heat that radiates down from the loft hatch in the summer and I was convinced it was the thing in the loft causing it but the HA said the thing in the loft is not wired into anything and doesn't belong to them and they don't know how it got there.

They reckon the heat is just from the sun on the roof and it does only happen in summer.

I'm allergic to dust so never go into the loft. It's only boarded out where this thing is and the test is all exposed insulation. I might order a dust mask from Amazon and investigate the thing further once I finish night shifts for the week.

Well it certainly looks like that loft vent @PickAChew posted.

You'll have to have a snout around up there.

Looks identical to mine and its a PIV (Positive Input Ventilation system) I'm about to turn ours off as it does make the stairs/landing area cold.

@RaisingH that looks similar to the thing in the loft. Could it be full? If it is a dehumidifier?

The man who lived here before us had COPD so that would make sense.

It wouldn't be full. It pushes air into the house. I'd get someone to see if it's still active.

@Frequency Mine doesn't collect water, from what I understand it pushes air from the loft into the house to help prevent damp/condensation somehow 🤔
We're in a 10 yr old new build and the only time I've heard it make a noise is in the middle of the night and it sounds like a fridge.

I was looking into getting one of these as they're great for air circulation. I have no idea why it's making a noise though. Do they have to be cleaned?

It looks like an envirovent, keeps the air circulating to stop mould and condensation on the windows. It is amazing. Ours beeped loudly a few weeks ago in the middle of the night and you’ve just reminded me of that. I’ve never cleaned ours or changed a battery. It’s mains powered.

I assume the filters need to be changed from time to time. I wonder if the alarm was telling us it was time to change the filter?

You have me wondering. Going to ask DH to investigate the filter although it hasn’t beeped again in weeks.