I bought a Lennox Elite series furnace in 2003 and a Lennox a/c added in 2010. Recently, when I select fan, nothing happens. The a/c and heat both work when set on auto, but sometimes I just want to use the fan in the evening. A tune-up company who replaced the blower motor a year ago said the fan relay must be bad and that I need to replace the entire circuit panel. I think it's a problem with the thermostat. Who can I trust to check this out?