I have a 3 year old Regency 2500 insert. I burn 2-3 cords of wood per year here in Eastern PA. I have it cleaned 1x per year. I am having a problem with the temp. probe. Model 911-185/186 which is the model number for the read out box and probe itself. The temperature is reading a lot lower (like half of what it should be when fire box is hot and full of good wood.) When I had the unit cleaned last year it had a lot of ash dusting around the probe when our original installer came to do the annual cleaning. He cleaned off the probe and assumed that was the problem. However it is still not any better at reading a temperature that should be much hotter. Do you believe it is the probe itself that should be replaced or the read out box that the probe connects to or both? I hear you are supposed to sand the probe end 1x per year which I don't believe happened when it was cleaned last year. Thank you in advance for your feedback.