I bought and used a new VC Encore throughout the entire heating season last year (2012). Ever since we've been using the stove this year the temps soar up to 600-650 within a couple minutes of starting the fire. We are forced to continually switch it over to the CAT to prevent it from getting too hot. Sometimes when there are only a few embers and the temps is down to 150 i put in a tiny log and the temp climbs right back to 600. There are no visible leaks, no smoke getting in the house, and the firebox looks good. Last year we could load it up half full in non-CAT mode and turn down the temp and maintain 450-550 no problem. Any suggestions or ideas as to what is happening would be appreciated. Thanks for reading!