I read a message posted on the board about the lennox furnace. That sounds similar to the same problem I am having. I have a Lennox Conservitor II furnace. There is a fan of some sort that comes on before the ignition switch lights the burners. The ignition "clicks" several times. Sometimes the burners light and sometimes they don't. But the "pre fan" keeps running. The actual furnace fan never comes on. If you switch the thermostat off and then back on - this will fix it - sometimes. At times you have to do it several times before it finally works. Is my ignition switch bad or is something else wrong?