I recently installed a Jotul F600 woodburning stove. I am having a difficult time getting the fire to take off. The draft valve is wide open and the side door is also left open. The only way to really get the fire to take off is to crack open the ashpan door which is a no no per Jotul tech support. I have taken the draft register off to ensure no blockage. The wood( Oak) has been cut in 8' logs for two years and chopped into firewood 2 months. My chimney is 18' verticle with 2- 45 elbows. I know of another that also recently installed the same stove and is having the same problem. He is the owner of a Hearth and Patio store and happens to be the one that sold me my stove. He had no answers so I offered to contact Jotul tech support. They instructed me to check the air valve, ensure the wood is dry (25% or less water content) and it should work. But it doesn't unless it has an additional draft source in addition to the air valve. Any suggestions?????