Hi everyone, I have had this heater for around 3.5 yrs. This winter the pilot began going out all the time and flickering while lit. It acts similar to when the propane is almost out except we are using new tanks. We tried bleeding the line longer and switching the tanks multiple times but nothing works. It has now gotten to the point that the pilot only stays lit if I leave it on pilot but as soon as I turn it to a number it starts sputtering and goes out. I can't find my manual and I'm not sure what to do. We considered replacing the thermostat but the store we got it from no longer carries the product. Do you have any suggestions as to the problem and how I could get replacement parts?