Thanks all – nobodys managed to fix a dodgy thermostat then? Problem is, at £70+ for a thermostat, mrs aracer reckons we should just pay £400 for a new oven rather than replace that.
Pretty sure it’s the thermostat – it is heating, but just not as much as it should before it cuts off. I have the model number – it’s the same as in the link above but with an 040 at the end instead of 050 (I couldn’t find one of those online when I searched, though I guess if I spoke to somebody at a supplier I might have more luck).
The trouble with the oven thermometer option is that the oven’s not even heating up that much when I whack it on as high as it will go (and until a couple of days ago it was working just fine to cook stuff, so there wasn’t anything majorly wrong with it).