Lennox furnace start up problem
My G24M3-75A-4 Lennox furnace seems to start okay. Inducer motor starts. After about 30 seconds a valve clicks and the flame starts. Usually after another 30 seconds Circulation fan turns on. But it is not happening and after 90 seconds flame turns off. Inducer motor continues running. After around 70 seconds Circulation fan turns on. From this point after about 50 seconds flame turns on again and runs like normally does.
I'm getting an error message of 4 blinks.
Thanks in advance for the advice.