Thermocouple Upon arrival inspected boiler: saw that thermocouple was not lit. Tried to relight thermocouple a few times. Thermocouple would not stay lit. Gas valve is receiving 24 volts. Bad thermocouple that needed to be replaced. Gave customer an estimate. Customer approved. Removed burn tube to start process of replacing thermocouple. Removed old thermocouple & installed new thermocouple. Re-installed burn tube. Put gas valve to pilot: relight burn: pilot lit and stayed on. Ran and monitored system operation. Cycled boiler on/ off @ 180 degrees. Boiler shut down on temperature: check flow @ x2 Hydro zone. System is back up for normal operation. Recommending to customer to follow up with routine maintenance for x1 Weil McLain boiler w/ x2 Hydro AH View visual findings from this job here - https://visionshare.xoi.io/?id=XA-2F41-FBB4F2C696834B9D98FB3889316B7662