Carrier furnace short cycling between Low and High heat
Just a quick update. I called another HVAC pro to come look at this problem. He spent over 3 hours assessing the zoning systems and trying to trouble shoot the short cycling. A/C coils are clean, the temperature rise was right in the middle of the recommended range.
He too was at a loss as to why the short cycling was happening. Thankfully the furnace did it while he was standing in front of it with the front cover off. He could hear the clicks from the relays. He wasn't 100% sure, but decided to change out the main circuit board.
So far so good. I hope this solves the problem, if not I'll be back asking more questions.
Thanks to all who shared some of their expertise with me.
A DIY Noob that knows just enough to be dangerous.