This is the most common complaint an HVAC owner brings to a second agency, and it has two very different causes that look identical from the outside.
The first is that the ranking is real and worth nothing, because the query it ranks for is not one that produces work, or because the map pack is taking the clicks above it. The second is that the calls are happening and nobody is measuring them.
Work through it in this order
What exactly are you ranking for?
Check whether the terms in the report are terms a homeowner with a problem would type. "HVAC maintenance tips" at position 2 produces reading, not calls.
Owned by Content
Is there a map pack above you?
On a local query, three map results sit above the first organic result and take most of the taps. Position 2 organically can be position 5 on the screen.
Owned by Local SEO
Are calls measured at all?
If there is no call tracking, "the phone does not ring" and "nobody counted" are indistinguishable. Fix this first; it is a day of work.
Owned by Tracking and attribution
Does the page ask for the call?
A service page whose phone number is in the header and nowhere else is asking a person on a phone to scroll back up.
Owned by Content
Do the attribution check before the content work. If the calls are happening and are not being counted, every other conclusion you draw from these reports is wrong.