Add Yahoo as a preferred source to see more of our stories on Google. replace blower motor or buy new furnace Q: My furnace recently started making loud noises and seems to have weak airflow. I think ...

If it be me I would wire up a sail switch. Contact closed when the fan is on (hot air)and independent to the furnace.<BR><BR><BR>And yes, taping into the low voltage thermostat wiring would work ...