Lennox furnace blower motor broke down on December 24, 2012 so we called in Pierrefonds Heating. They charged $564 to replace the blower motor (parts & labor) and had our furnace up & running again... for 40 hours. 2 days later the furnace tripped the electrical breaker, and upon resetting the breaker the brand new furnace blower motor did not start up.
Naturally, I called Pierrefonds Heating and seeing as it was an emergency they sent over a technician on December 26 at 11:30pm. This technician was very rude and took a look at the furnace and told me the "fan control relay" on the main control board is burnt. I asked him to explain how that would happen and that I was very suspicious that the new blower motor was likely the root cause of a fan relay that had been working fine for over a dozen years. He said there was no coincidence (really?) and could not explain to me logically why. I am an Engineer with many years of experience working with electronics and far more complex micro controllers than a basic 15 year old furnace control board. This technician could not convince me with any evidence that the fan relay did not in fact burn out as a result of the new fan motor that was installed less than 40 hours prior. He also did not test the motor or verify the motor leads to see if all the electrical circuits were closed and that nothing was open or shorted in the motor itself.
Pierrefonds Heating now refuses to take responsibility for the control board and wants to charge $595 for the control board plus labor. I also tested the motor's leads and have determined that there is an open connection, something the technician should have done but did not do. The open connection on the motor was likely the root cause of the fan relay malfunctioning as it did. Relays are simple electric devices and don't explode or short circuit unless as a result of an external electrical failure. In this case, the external electrical failure was either the open connection in the motor or the installation itself. Something Pierrefonds Heating absolutely refuses to admit to.