Is my fridge freezer working ok?

Borrowed a thermometer to check the temperature. If I open the door just for a minute the it goes too warm. I have it on lowest setting so am worried. It's second hand and quite old but a Bosch.

 

Then don’t open the door for a minute .

 

From the photo, it looks like you're measuring the temperature of the fridge. Opinions vary slightly as to the optimum fridge temperature but mostly somewhere between 2C and 4.5C although temperature often varies a little throughout the fridge cabinet - especially with glass shelving (as you appear to have) and no air circulating fan (which your fridge may or may not have).

Your thermometer seems to be reading about 6 or 7C but as foxhole has said, leaving the fridge door open for more than a few seconds will cause fridge temperature to rise. If you want to get an accurate temperature measurement, place the thermometer half-way back on the middle shelf, close the door and leave for a couple of hours (assuming the fridge is already cold and nothing warm has recently been put in it). Then open the door and immediately take a temperature reading (don't take longer than a few seconds). If the reading is still above 5C then either lower the temperature some more and repeat this process (you say the fridge is set to the lowest setting but it looks like the control could be set a little lower?). If, even on its coolest setting, the temperature is still above 5C then something is wrong with the fridge or it's being used in an unsuitable environment (i.e. environment too hot or too cold).

 

That type of temperature gauge (mechanical) can be wildly inaccurate, but it shows about the correct temperature for a fridge. A few weeks ago, I left the freezer door ajar, so decided to buy an alarm. This is what I bought...

https://www.ebay.co.uk/itm/TM803-Fr...m-Thermometer-Temperature-50-70-/122238036405

It is perfect for the job and seems very accurate. It can be set to alarm on too high a temperature, or too low, or both. I have it set to alarm if the temperature rises above -14C, with the sensor fixed to the side (inside) of the freezer. It triggers if the freezer is left open for more than a minute, bleeps a few bleeps, then pauses for a minute, then repeats while ever the temperature is too high. It has a long lead between sensor and display - my intention was to have the sensor in the freezer which is in my utility room, but have the display in my kitchen where it could be heard. I didn't need to do that, it was loud enough to be heard through the wall.

 

Usually setting 0=warmest and setting 5=coldest, can't tell what the dial is at?

Ps the dinner plates look ready to fall out

 

Ketchup in the fridge is just wrong.

 

Reduced fat mayonnaise is more of a crime