hi have this cooker lesuire Victorian Delux twin and the FSD has been changed due to the flame not rising. Flame is rising now but taking a long time to rise. the flame seems to be too small so not heating up the thermal couple. have used a blowe tourch for few seconds on it and the solinoid opens and its works a treat. any ideas thought it might be the tap. Have taken out burner and cleaned it all out not blockages. Any help would be great.