Is it ok to leave a wood pellet boiler off for a long period e.g. a year or more? I'm concerned about posible condensation/corrosion. The system has about double the recommended minimum level of Fernox in the water so corrosion from within should not be an issue. I can remove the entire burner assembly and the ash pan so that air can pass freely up through the boiler to the flue, keeping it swept with fresh air. The boiler is within the garage, not outside.