Quick question for you guys since I don't want to bug my builder on a Sunday. Hoping it's something silly.
When I turn on my "ventilation" switch, normally the furnace fan runs and blows cool air and it's connected also to the main floor bathroom exhaust fan. That is how it has worked 100% of the time up until today. Now, when I turn on the ventilation switch, just the bathroom exhaust fan runs, and the furnace/fan does not turn on at all.
Status light on the furnace says it's operating normally. Breaker is obviously fine as I can see the status light. Anything else I can check?