A few days ago, I was testing this furnace. The homeowner had some duct work done so we checked the systems performance with an airflow test and static pressure readings. I was in the middle of checking the static pressure readings when I noticed a small movement out of the corner of my eye.
I paused, and looked around half expecting to find a spider or mouse that found themselves trapped by the freshly sprayed foam insulation. To my surprise (and relief) it wasn’t any sort of creature. The suction line on the unit was jumping around.
It was barely noticeable as the line entered the cabinet, but as I traced the line upward, the shaking became more apparent. While this is a bit outside of the general scope of our inspections, I can assure you that this is a mechanical problem and an HVAC professional should be called in immediately before serious damage occurs. Take a look at the video and see if you can spot the shakiness.
If you’re an HVAC contractor, and you have a guess at what’s going on here, please post a comment below. I’ll update this page as soon as I find out what the solution was.