My main fridge is about nine years old and starting to look a little daggy. Don't get me wrong I think it still does a marvellous job and wouldn't dream of replacing it, but I was a little concerned that I might be paying a higher price to run it.
Why you might ask? Basically over time the seals around the doors start to deteriorate. This means that your fridge can't keep the cold air in and has to continuously replace this cold air by running the motor which then costs your money in energy usage.
But how do you know if your seals need replacing? I had somewhere in the back of my mind that you place a piece of paper between the door and the fridge, close the fridge door and then try and remove the paper. I did this, but I could easily remove it from multiple locations around the door frame for both the fridge and the freezer. Either my seals were completely dead (which I didn't think was the case) or there was something wrong with my method.
After a quick internet search, another method suggested was to place a torch in the fridge at night, turn off all your lights in the vicinity of the fridge and see if you can see the light coming out of the fridge. If you can see any light you need a new seal. I tried this method last night and couldn't see any light, so currently I am assuming that my seals are ok. See if I can come up with any other methods to test my fridge and freezer seals.
Maybe worth a try at your place.