Fridge door alarm

[jamma-plusser]

Can anyone recommend a fridge door alarm which will sound if the fridge door is left open for a period of time?

Either that or a decent fridge thermometer with built-in alarm.

Thanks

[Bob Eager]

I used one of those inside+outside thermometers, and ran the 'external' detector into the (in my case) freezer. Found one with an alarm on it so if the temperature rose, it'd sound.

[Mike Lane]

jamma-plusser wrote on Aug 15, 2010:

I use two of these - one for my fridge, the other for the freezer. You can set alarms for both upper and lower temperatures if you wish. They work very well.

[Dave Starling]

I bought something similar but gave up as I couldn't get the wire to stay stuck. Since then I've been using a kit based around a 555 timer. I got it from the internet for about a tenner and it looks like a school project but I couldn't/didn't have the time to knock it up myself. Door to fridge opens, microswitch opens and contact closes, giving power to the circuit. If door remains open for longer than 20 seconds a sounder emits a shrill alarm that can be heard upstairs. My fridge door can be left ajar around 5mm without the magnetic strip having enough strength to close it. The microswitch is positioned at this point to just catch the 5mm gap. It works well and soon everyone in the house learnt to properly shut the door. I need to wire another microswitch in parallel to the freezer door to monitor that one too.

Dave.

[Mike Barnes]

I have made something similar but the timer module was from Maplin rather than eBay, and I use a magnetic sensor (designed for burglar alarms[1]) rather than a microswitch. The box containing the batteries, timer module, and sounder also has an LED indicator which lights up during those (60 in our case) seconds, to show that the batteries are in good shape.

I gave up long ago on temperature-based alarms. They don't distinguish well enough between door-open and auto-defrosting conditions, and they aren't quick enough to ensure that someone is still around to hear the alarm.

It beggars belief that fridge/freezer manufacturers have never built a solution to this problem into their products. Our fridge-freezer does have a door-open alarm, but it only works if the door is left wide open. So it's simply a nuisance and serves no useful purpose whatsoever.

[1] Most alarm door switches have only make-when-closed contacts, which are not right for this application. But it's possible to get them with make-when-open contacts, e.g. from CPC.

[John]

Why not address the fact that someone seems to be leaving the door open? To the person that claims the door is a bit stiff then try a drop of oil and ensure that the fridge is level.

[Mike Barnes]

John :

In this household it's not the door that's stiff, it's the *drawers* that are too heavy to slide easily, or their contents snag on something, or both. With the drawer not quite fully closed, the door can almost close, but not quite. The problem arises mainly in our freezer but it can also occur with the salad drawers in the fridge. Or something in the fridge door hits something else on a shelf just before the door shuts completely.

It doesn't happen very often, but once is too often.

[Mike Lane]

Dave Starling wrote on Aug 15, 2010:

Yes the wires are a bit untidy, but I don't mind that and luckily for me there's no one else around to complain ;-)

That sounds ideal. A feature like that would cost a pound or two for a manufacturer to add to a fridge. I do like to know the temperature in my fridge though. I wonder why thermometer read-outs and the like are so rarely provided?