Arrived on site to perform annual maintenance and safety inspection on the plumbing system. Checked the master bath for any issues and did not find any. Flushed Navien hot water tank. Checked kitchen for any problems found none. Inspected crawlspace and did not find any problems. Insured customer was receiving hot water upon leaving. HVAC: Cleaned and Serviced furnace, both top and bottom compartments were very dirty when I opened the furnace doors. Began by testing my inlet gas pressure which gave me a reading of 8.55. Tested my flame sensor was pulling 2.2 Microfarads. Inducer was pulling 1.02A. Blower was pulling 3.80A. Measured for my delta t which gave me a air temp differential of 45 degrees. Tested for CO found none. Insured everything was working properly.