We used Laird and Son as the previous owners of our house had the furnace installed by them.
I'm not sure if this was normal, but they re-scheduled our maintenance appointment 3 times after not having it written down on their work order during the first visit. The rescheduling was somewhat problematic, as there was not a lot of notice in each case.
When they finally showed up, the first person to inspect the furnace, commented that the previous installer (now a former Laird and Son Employee) did a really poor job installing the furnace. I had to ask him to repair a number of issues with the ducting and poor joins. When he was done the maintenance he stated that there was a leak in the gas line and he had to get someone else in to repair the leak as he couldn't do it himself.
The second person showed up and said that the fitting was old and they would have to replace it with a more recent type and left. They nicely provided me with Electric Space heaters. In the afternoon, two older service men showed up, took a look, tightened the pipe and said it was good to go.
I asked why the first two guys couldn't fix the leak, they said that they didn't know - they simply tightened the valve and it was fine.
This experience did not inspire confidence in their operation or the types of people that they are employing.
UPDATE - Laird in Son did manage to get a hole of me, I spoke with their sales manager who did indeed offer to 'make it right'.
An appointment was booked, the two technicians came by on time - as promised and plugged up the holes in the duct work around the furnace. This has led to better heat distribution and less wasted heat in the furnace room. I appreciate the fact that Laird and Son followed up and were willing to correct what needed correcting.