We recently moved into a 7 year old townhouse with a Trane gas hot air heating system and AC. OUt HVAC maintenance person installed a new blower motor, because the air flow was weak. The air flow is fine, but we get occasional clicking/clinking noises coming through the registers. These are sporadic, can occur at any time in the cycle (starting or stopping), and whether we are heating or cooling. The HVAC person has looked at the furnace and AC, and they have nothing loose. Any suggestions where to look for the problem?
I checked with my HVAC service person, and he assured me that the damping grommets were in place and that the new motor was identical to the original. However, I found out that leaving the fan on ON rather than AUTO solved the problem, at least for now. With this information, I called technical support from TRANE, and was advised that the problem was probably in the fan (squirrel-cage) or its mounting; that it was getting slightly out of line when starting or stopping. My HVAC service man will pull and replace the fan next month (between the busy cooling and heating seasons) and we home this will be a permanent solution.