Our PF100 is about 3 years old and has worked great until about 3 weeks ago. We have had a cold snap with temps below zero for a few days. Can't get the house about 66 in the day, drops as low as 55 at night with stat set at 75. We have never had an issue before now even with below zero temps. Same pellets, cleaned top to bottom, tried softwood pellets vs normal hard wood. No luck. Noticed today our upper baffle has corroded significantly with a large horseshoe shaped 'hole' in the top. Could this effect the heat output? Is it safe to burn while waiting for a replacement? Thanks for any help!