Burglar alarm set off by fridge

[stripeymonster]

Just got back to our holiday rental after a meal out. Got through the door to hear the fridge beeping, opened fridge which bizarrely set the burglar alarm off. Can't get hold of the owners. It has stopped now but went off twice each time after opening the fridge. Any idea why? There are no instructions left by the owner as how to switch the alarm off. Now I'm worried it's going to go off on the night. Or when I next open the fridge.

Weird.

Maybe they are really keen on someone not nicking their food.

Alternative explanation is that when the fridge door is opened, the fridge compressor starts up to start cooling it. This causes a slight voltage drop, which puts the voltage below the threshold to cut the alarm (a lot of alarms go off when the mains goes out).

However this doesn't explain why the alarm doesn't trip when the compressor cycles on the fridge with the door closed. Maybe its because the start up mode demands less power when the door is closed.

Anyway, I would try to make sure any other appliances are switched off (as well as lights) to reduce the power demand when the fridge door is opened and see whether that helps.

Is it because the sensors are above the fridge, aimed at the door, but aimed up high to avoid being set off by cats in the middle of the night?

Possibly on the same wiring circuit. If the fridge is faulty it might be causing issues with the alarm. Can you see where the consumer unit is and see if the alarm is listed along with downstairs sockets? Mine is on the same circuit as the upstairs lights, I think because the control panel for it is in the loft. Probably where they got the supply from.