Client stated no heating -Technician found flame sensor to be very dirty, causing the flame to night stay lit for very long -I cleaned off sensor and igniter -Also, the flue vent for furnace was not sloping up, it was sloping down and then back up which is not how it should be -It was a flexible vent, so I simply readjusted to to make sure it sloping up entire time -The simples repairs made today could have been prevented if client was in a maintenance plan, so she is now apart of our Comfort Club