Oven Temperatures.

[Gruney2 Profile]

I raised a similar topic many years ago, but this is slightly different.
My oven has conventional and fan facilities, but there is a limit to the size of the cooking tray you should use for fan. I've noticed that when using the conventional mode, things can sometimes be overdone, and have been checking the temperatures with an oven thermometer - fan is spot on, but conventional cycles quite a bit. I was told this is normal, and this is how the correct temperature is maintained.
I imagined that this meant that the temperature would sometimes be below, and sometimes above the chosen figure but would, on average, give the correct result. This doesn't seem to be so. Yes, it cycles, but it switches on when the oven temperature drops to the one selected, and then rises by at least 20deg before switching off. Is this normal, please, or do you think should I compensate for this quirk by selecting a slightly temperature?

[Suelle Profile Website]

When I last read up about this I was quite surprised by the amount of tolerance allowed on oven temperatures. Have you checked the oven at a whole range of temperatures or just at one point eg 180C?

If you're sure that your conventional oven is consistently higher than the temperature you've set, then cook at a lower temperature.

[Gruney2 Profile]

Thanks Sue - the difference above the selected temperature actually increases with that selected ie it seems to be a percentage rather than a fixed amount - at 230deg, it reaches 270deg, before dropping down to 230, and starting again. Now i know it shouldn't be as it is, I'll do a bit of experimenting.
It's not just the food that could be ruined - I have a pretty expensive 3ply stainless casserole which is ovenproof up to 220deg, which could be compromised.

[aero280 Profile]

You may just need a service/deep clean. The thermocouple temp sensor may just be dirty or a bit blocked. OK if air is being blown past it, but comprimised if it’s relying on convection.

[jeral Profile]

A casserole dish is probably used for long, non-fan things as they hold heat so fan would be irrelevant. Perhaps take comfort that the "up to" temp is likely to have a fair few degrees of tolerance given no two ovens are the same, but a lower heat setting can't hurt and probably makes little difference over a long time.

It seems nonsense to me that a casserole dish wouldn't go up to 250C (being domestic max), unless it has composite knobs or fixings maybe.

For bakes or short things, perhaps always use fan?