We have a Chatham as well, installed back in September, and I've only run it on #1, except for bumping it up to #2 on the really cold days we had last month. (House is pretty well insulated, so that's different from your setup.) I just wanted to present our dealer's advice, for what it's worth. He recommends running the stove only in manual mode (constant run), for the same reason of saving wear and tear on the ignitor.
I haven't bothered to hook up a thermostat, partly because of his advice, partly because I've been lazy, but I don't know if sparing the ignitor is worth worrying about all that much. Despite the fact that I'm around during the day, the stove has run out of pellets many times, or I have had to shut it off for cleaning. I just don't know how much "wear and tear" I am preventing by running on manual. (Another factor is that I have no idea how old the installed ignitor is, since the stove was a floor model for several years. The dealer may have put a new one in, guess I should ask, huh?
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In any case, I found an AMP 300W ingitor at (broken link removed) for a quarter of the price of the OEM part from Enviro, and have it standing by, just in case. If I ever have to install it, we'll see how it compares with the OEM, but at 1/4 the price, I could afford to go through a few ignitors, I figure. If I do get a thermostat, I'll probably run the stove in high/low mode, rather than in on/off, because it's nice to have the constant heat.
Mind you, all this is coming from a pellet stove newbie, but these are my thoughts at the moment. I really love this stove, it does a great job. Dad loves sitting in front of it, he spends several hours each day. And so does the dog!