Came out because the customer was concerned about an error code being displayed on the thermostat. I looked up the cod (206) and the code is stating that the gas valve 2nd stage relay has failed. This will not allow the furnace to ramp up into stage two. The solution to this problem is to change the control board that’s not send the signal got the furnace to ramp up. it’s working just fine in W1 but not W2. I jumped out W1 and W2 and the furnace did respond and went into stage two. I ordered the control board from lennox in peach tree corners. It will not be available for 2-3 weeks. The part #27p17