I/W Upon arrival spoke with customer who’s informing me that the boiler stop working completely over the weekend. Customer tried to reset boiler but boiler still did not operate. Inspected boiler saw two zone calling for heat but the boiler is in standby mode. Check boiler zone panel and confirmed zone is calling. Check all safety controls. Found safety ok and not tripped. Found end switch wire @ zone panel touching metal casing. Causing a short to ground. Once wiring was corrected boiler fired and began to operate as it should. Wires were re-spliced, boiler was ran, tested and monitored for over a hour. Cycle boiler on / off multiple times and confirmed boiler shutting down on temperature. Labeled all zones, inspected thermostat operation and checked radiators. System is back up for normal operation @ this time.