Tips for wiring for a residential thermostat include studying the wiring instructions on the installation manual or the appliance, turning off power to prevent shorting wires together, wrapping unused wire and placing splices in visible locations. Always dispose of hazardous materials responsibly.
If you are not sure which wire in the system goes to which terminal, studying the installation manual or the wiring instructions on the appliance helps clear any doubts.
Before working on the thermostat wiring, turn off all electrical power involved with the house’s heating system. An appropriate test instrument, such as a Volt/Ohm Meter, helps confirm that power is off in the working area. Shorting thermostat wires together or to ground may damage components in the thermostat itself or in other components in the heating system.
It is better to wrap than to cut back an unused wire around the main thermostat wire outer jacket, because you might need to use it later, explains InspectApedia. Leaving bare wire ends exposed risks accidentally shorting out something inside the thermostat or other control devices.
Always make thermostat wire splices in fully visible and accessible locations. Hiding such splices in a difficult spot may pose a safety issue. Use a longer wire to avoid having to leave such a splice in a hidden place.