Do gas lines need to be cleaned - blown out or something - periodically? My water tank doesn't always ignite when I turn it up, although the pilot is on,, and seems like the feed to my stove is becoming erratic - my burner's making noises like "pfut, pfut, pfut" as though not getting a steady supply. And now my oven won't heat over 300, though that could be a completely different issue. I guess my question is twofold; who can I get who's qualified to check out the lines (not a "handyman" but rather a certified "gasfitter" - because I'm terrified of gas to begin with). And then, who services stoves like my little 4-burner Acros?