I have a a 1998 Elddis Hurricane GTX fitted with a Rose 6070 oven. It will light on its first setting but will not pick up to a full heat flame. Is it the Flame failure device, can I replace it or do I need a new or secondhand oven?
Is your regulator OK? If the gas rings have a flame that comes off the ring as well it might be the regulator, allowing the gas to come through at too high a pressure.
If I understand you correctly, the oven will light and operate on a low setting but will not not operate correctly on a high setting.
As Chris says, the flame could blow out from too much gas, which points to a regulator fault or just the wrong regulator.
Or you may not get full gas flow. A longer list of possible faults this time, a faulty regulator that is restricting flow, a partly blocked main jet, or a faulty flame-out sensor.
The possible cause is a blocked jet due to grease from cooking but I agree with John, it needs sorting by someone who understands the system as there are several other possibles.