I performed a single system heating maintenance on a 2017 zoned gas system. I checked amps, capacitors, ohms, electrical, cleanliness, and safeties. During my thorough evaluation, I noticed that the ohm value of the hot surface igniter is reading way below normal range. It is only reading 14ohms and indicates a lack of resistance. I took a photo of it showing a huge white spot. These are signs that he igniter does not have much life left. Also, I had the furnace trip on the high limit switch during operation. I confirmed that the air was not hot enough yet to result in tripping. The high temperature switch is tripping before its 190 degree limit and allowing the system to come back on immediately. These switches are design to cut out and allow time to cool the switch by 30degrees. I verified that the warranty is expired and priced these failing parts. I offered to install surge protection, as well.
