I have a Honeywell T8011R programmable Thermostat. The fan has two settings, Auto and On. It seems the "On" doesn't work. When the temperature falls below the setpoint the heat kicks on and the blower works then, but when I switch to fan "On" it still kicks off after the house heats up to the setpoint. Any ideas as to what is wrong? I checked R to G and didn't get a voltage reading. Will I have to replace the thermostat?

Jumper R to G. If the blower runs then the problem is in the t-stat or wiring.