Upon arrival customer stated that heat was not working for 2 year old furnace. Did full evaluation of system and found several issues with system. There was active water leaking out furnace and into the system. Found that drain port inside system was not secured properly and the water from 90% furnace has been leaking in the unit rusting the unit out very badly. The flue pipe was not connected into the rubber fitting, had a small opening. Reconnected flue pipe. As inducer draft motor is running there is water inside compartment moving around. The pressure switch tube was filled with water that caused heat to stop working, system does not have 90% drain collector box installed on outside of cabinet to the condensation pump. Cleaned flame sensor. Due to all the rust in system recommended changing out furnace, customer had this furnace installed two years ago, she is going to get back in contact with company who installed it about repairs needed. Repairs needed are flue pipe correction on