Most sources say temperature should be between 3 and 5 celcius. Too low and stuff at the back will freeze. Too high and (obviously) the benefits of refrigeration start to fall off.

Auto defrost in a normal fridge is mostly about draining the condensate that would in the past have gone into a drip tray that needed emptying. It does not involve heat.

I presume it's air temperature you're measuring which will fluctuate, particularly in current weather where air is 25-30C. My own theory is that it's the temperature of the contents thatr matters and I think (say) a bottle of milk that's got down to 5 or less won't warm up that quickly even with an inrush of ambient air.

The first fridge/freezer we had with auto-defrost had to be replaced because the warm-up cycle didn't last long enough for the condensate to drain fully, so that the drain holes blocked with ice. I don't know the frequency of auto-defrost, but every day seems rather too much.

Fridges generally are advised at about 5°C, but the range you are seeing should be OK.

To make the most out of a fridge or freezer, it needs to be situated in a reasonably cool environment, and, very importantly, to have sufficient space around the unit (including behind and above) for air to circulate, because that is how (by convection) they reject heat to the room to keep the inside within the desired temperature range. This should be coevered in the unit's manual.

Obviously the temperature varies quite a bit within a fridge, hence why the manual recommends certain foods be placed in certain areas. Sometimes, the specific placement of a separate fridge thermometer can make a huge difference as to what temperature it reads, in addition to how well the unit can perform in summer conditions when the room it's in is much warmer.

Additionally, it's best to keep an eye on that thermometer in case the temperature starts rising without any significant increase in room temperature. This could be because either (or more than one reason):

1. Ventilation around the unit is poor, and the unit is already working at full chaff and cannot do any more to keep the contents at the desired temperature, even if you turn the dial to its minimum temperature setting.
2. The door is not shutting properly (due to misalignment when being installed or a poor fit and finish on the general design) and for similar reasons to 1, the higher room temperature means it struggles to maintain its internal set point.
3. There is a leak of refrigerant gas (like in a car) becaue the unit is old, a faulty part or weld has allowed some gas to escape (as happened with my previous fridge) and the unit again cannot now cope with higher room temperatures.
4. The fridge is overloaded. Unlike freezers, fridges do not like being filled up to the gills and the door left open for ages whilst you fill/use it. Air needs to circulate within the fridge as well (see the manual). Sometimes restocking a fridge will mean for a time the temperature will inevitably rise whilst the new food cools down.

That being said, if it only goes up to 7degC, then it's not too bad - just make sure that you keep an eye on temperatures generally and look at and smell food and drinks (milk) to see if they show signs of perishing, and keep them in the correct area.

To help keep the room at a reasonable temperature, try opening the window or ventilation slot/flap above it if safe and ok on security - but only after dark when the outside temperature drops to below that of the room - counter-productive otherwise. I also will not do so if the light needs to stay on in the room because it attracts insects (especially moths).

My (ground floor) flat's windows have ventilation flaps above them, so I leave them open overnight when its cooler outside - even last night (18degC to 15degC outside) it was enough to reduce the room temperature by about 1degC more than if they were closed.

Sometimes I stay up an extra 30-60 minutes in summer evenings with the lights all off and the windows open to let in some cooler air to help, then shut them all (not the vents, which stay open until morning) when I go to bed.

If you live in a house, then if you can do this, open windows (and vent flaps) at both top and bottom floors as this will encourage the warm air to rise and leave the building and cooler air to come in at ground/lower floor level to replace it.

When you open the refrigerator door it allows in the (currently) hot air. When the door closes the refrigerator must work to cool the air inside back down to the given setting. Hence the fluctuations. If it is fluctuating throughout the day when not being opened, then I think that that is just a result of the ambient air temperature effecting the temperature within the refrigerator.

At least that how I understand it....could be completely wrong!

Sammy, when winter comes, please don't put your head in the oven....

Hi Martin

If you just keep it somewhere between 3 and 4 on the little dial it will work well.

The higher the number on the dial - the colder the fridge. But somewhere near 4 is good.

I used to work in the prarmaceutical industry and they defined fridge temperature as 5 +/- 3 degrees C. So that would work out as anywhere between 2-8 celsius.

Hope this helps

I've never come across this issue before but my refrigerator didn't work clearly due to refrigerant leak. It is caused by holes or cracks in the coils that circulate the refrigerant. That's it's important to be careful as it may be harmful to one's health. To identify this problem I bought detector, here is a great review

Obviously your spam slices didn't go off...

Forget 'leak detectors', below are two sure-fire wasys of knowing your fridge has a refrigerant leak:

1. The normal operating temperature cannot be maintained and it keeps rising over time;

2. You can smell smething near the unit that also gives a bitter taste on your tongue - that's the refrigerant escaping in gaseous form.

Time to change the unit, pronto if either start to occur. Any diagnosis and repair would be more than any of us could succesfully carry out and would be prhibitively expensive to get a technician in (unless they could do under warranty - more likely a replace-it completely job).