ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades UK cooker/RCD problem

I have an old but virtually unused AEG cooker. When a ring or oven/grill is switched on the RCD trips after about half a minute. Even if the ring is turned off it will not then reset. After a couple of hours however the cooker works for 30 seconds, then trips off. Checks with a multimeter reveal no obvious anomalies.

Is this a common problem? Can it be fixed?