I have a Carrier 48AKD060 and u cannot get the econ working. I have verified my parameters with tech support. The main base board was replaced due to the eeprom failing. The run status shows the "Supply Fan Not On 30s-yes" and this is locking out the econ. Now tech support is telling me this is a fixed algorithm (essentially a programmed time clock) and cannot be bypassed, change, etc. Here's the kicker, my supply fan has been running for 6 hours. Anyone know if that is true. I can't belive fan proving isn't done by a DP, or current sensor.