Upon arrival, I found the system off with the furnace door off. I turned the unit on and began testing. I observed the red light for heat was flashing on the zone board. After a bit of time, the purge light began to flash and it starting the heating cycle. From past experience, I found this to be sensor related. I ohmed the discharge temperature sensor and found that it was reading 0 ohms. I provided a price to address the issue. Customer approved the replacement of the sensor and I tested the system afterwards. The purge light was no longer flashing and the system is ful,y operational
