Paterson-Lange are very reliable. We have been using their services for over 10 years for our four vacation homes in Niagara on the Lake. We have had them install 3 furnaces, and 2 Central AC units across our homes in the town. They are competitively priced and always honest about what work is needed. They also service all of our furnaces, and gas fireplaces each season. Whenever we have had an emergency with a furnace in the winter, they have sent someone within an hour.
We highly recommend them!