Two ways this work shows up.
Thermostats are controls. The visit depends on whether the existing system has a problem, or whether we are putting in new equipment.
On a service call
A thermostat that is not controlling the system, or a system that is not responding to the control, is a service call. We come out and diagnose. The cause may be the thermostat, the wiring, or the equipment itself. We start from what the house is doing, not from a brand list.
Service calls and repairs
On a new system
When we install or replace a system, the control is part of that install. We look at the house and the equipment we are putting in, then set the control to match so heat and cool call the right way from day one.
New systems