I have a Sterling Europa 460, less than two years old. Last year, around February, I couldn't get the oven to light for dinner on first night. Breakfast was OK! Assumed that it was the fact I used butane so changed over to propane. No problems until last week. Same problem. No gas getting to oven, hob fridge or water heater. Removed pigtail - left tank for a couple of hours, reconected pigtail - everything fine. Dinner went fine but come breakfast same problem. Anybody any idea what the problem is and, more important, what the solution is?