To be clear, the furnace maintains the heating cycle until the target temperature is reached. Once it kicks off, it stays off until I go to the basement to reset it. It will not come on automatically once the temperature falls below the target setting. With these cold temperatures and a target heat of 70, we go to bed with everything working fine and wake up to to 50+ degree temperatures in the new addition. We have temporarily bypassed this problem by setting the target heat higher to 73 degrees. The system has difficulty warming to the higher temp and hence stays running through the night. These appear to be the same symptoms from our last repair of the pressure switch. I understand something else may be causing it, but we have to consider the pressure switch may not be playing nice in the sandbox or potential problem with the circuit board.