I woke up this morning to a cold house, the furnace was on but it was nonstop blowing cool air. I called a heating guy and he replaced a part but said by furnace is unsafe and setting off a carbon monoxide signal on his electronic gadget. He said the furnace needs to be replaced and under no circumstance should it be turn on so he turned it off. I'm now waiting for another guy to give a second opinion. Anyway the furnace I was recommended to install is an Armstrong, I never heard of the company. Anyone know anything about the company, is it any good?