lennox furnace

12-14-2010, 12:48 PM	#1
foot Newbie   Join Date: Dec 2010 Posts: 1	lennox furnace My lennox furnace will only work when the fan is on all the time. It will not come on when it is set on automatic fan. Do I need a new circuit board? Can I install it myself?

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12-14-2010, 05:09 PM	#2
Marty S. Member   Join Date: Oct 2009 Location: Nebraska Posts: 2,290	lennox furnace The way you test is to turn the heat on. Put a meter on the blowers heating speed tap and neutral. 45 seconds after the burners ignite you should have 120 volts present. No voltage is a board issue, yes voltage but no blower is a motor issue. Yes you can replace part yourself.