Re-secured the thermostat to the wall with drywall anchors. Thermostat displaying low battery, installed Google C wire adapter amd changed batteries. Performed heating maintenance. Changed filter. Set stage two timing to 12 minutes. Cleaned flame sensor. Flushed condensate trap. Checked collector box drain ports. Fixed a small condensate leak on the right side drain plug. Set gas pressure to 1.7" on low fire and 3.5" on high fire with the burner cover off for atmospheric reference pressure. Everything else operating within manufacturer specifications at this time.