We have a 2 year old Olsen BCL145S furnace. installed in the basement of our 90 y/o, 1300 sq. ft. house. During a heat cycle, the burner cycles on/off 2 or 3 times; the blower sems to cycles properly. Limit switch settings are: off-100, on-130, high limit-230. We use pleated filters, replaced regularly. When it was installed, we replaced the "octopus" of heating and cold air return ductwork with rectangular central ducts, with branches for the individual registers. Lost a lot of intake and outflow sq. in. when we did that. Tried adjusting the limit switch to off-90, on-115. Didn't help. Could the problem be inadequate ductwork? Would it help if I vented some heat into the basement? I am worried about premature wear on the furnace. Should I be? Thanks for any help.