Honeywell T4H110A1021 T4 Programmable Thermostat Installation Guide
Quick Start Installation Guide
Compatible with 24-230V on/off appliances such as gas boilers, combi-boilers and zone valves. Not compatible with 230V electric
heating.
Installation in 3 steps…
Must be installed by a competent person. To ensure your safety make sure the mains power is switched OFF before
accessing wiring.
Wire the Thermostat
Find a suitable wall location away from draughts, direct sunlight or other heat sources, and where cables can be run from the boiler to
the thermostat.
A) Separate the wallplate from the thermostat, and using a screwdriver open the wall plate terminal cover to connect wires.