Posted: Tue Jul 28, 2020 2:43 pm
I have a miller MGC-80-1 furnace that still works good up until this summer when we were using the air conditioning. The blower motor doesn't shut off when it reaches the preset temp on the thermostat. We have to move the toggle switch that controls winter-off-summer to the off position. I replace the thermostat and the fan control/high limit switch and it does the exact same thing as before. I called a furnace repair man to come out to diagnose further. He said the relay is bad and they tried to get the part but can't find it. Does anyone know the part# or if you can cross reference this relay part with another that would work to fix this furnace. I realize this is an old furnace but it still works for what I need it to do with the exception to this new issue.