Hey, I think I remember you from last year when you were in the buying stage of your owb. So how do you like it? From what I've seen heatmaster is a good looking owb. Did you go with the standard or is this one the gasser? How much wood did you use?
Anyway for your question, my Hawken/global is stainless also. At the end of season I get all the ashes out and scratch the loose creasolte/ash crust from the back where it is hard to get to in season. I send a water sample to certified labs, (so far so good 4 years running). I replace the chimney cap with a 5 gallon pail, turn off the circulator. Also I usually will turn the pump on for a few minutes 2-3 times during the summer.