My GF300 has been working well for several years. I have it inspected and tuned up every fall. After using it all winter, the flame went out last week. I turned off the gas, went out of town. When I came home, I relit it and it worked for 24 hours. Then, the flame went out again. I checked possible outside vents and didn't notice anything, but don't know what to look for either. Can I safely light it again tonight or is the stove trying to tell me something?