Found mold in the supply plenum. Wiped out the mold and installed an APCO air purifier to kill mold, bacteria, germs, and viruses. Signed the customer up for a Comfort Club Membership and went ahead and performed heating maintenance. Did not change the air cleaner filter. Found the system operating with a worn ignitor. Recommended repair. Recommended water safety to protect the furnace from water damage. The customer wants to wait. The system is heating at this time.