Honeywell RTH1120 Owner's Manual - Page 1

RTH1120 Non-programmable Electronic Thermostat Installation and User Guide 1. Introduction The RTH1120 non-programmable thermostat can be used to control: • a gas, fuel oil or electric furnace - 2 or 3 wires • a central air conditioner - 2 or 3 wires • a hot water system with or without pump - 2 wires • a millivolt system - 2 wires • a central heating and cooling system - 4 or 5 wires Note: This thermostat is not compatible with heat pumps or multistage systems. q Wrap the wires around a pencil to prevent them from falling into the wall. r If the hole in the wall is too big, insulate it using a non-flammable material in order to avoid air draughts behind the thermostat. 2.2 Installing the New Baseplate For a new installation, choose a location approximately 5 feet (1.5 m) above the floor and on an inside wall. Avoid draughty areas (top of staircase, air outlet, etc.), dead air spots (behind doors), direct sunlight or areas near concealed pipes or chimneys. Display Adjustment buttons Backlight button n Remove the thermostat faceplate. o Loosen the locking screw to separate the thermostat from its baseplate (the screw cannot be completely removed). System operating mode selector Fan operating mode selector Features • System operating mode selection: heat, cool or off • Fan operating mode selection: automatic or on (continuous) • Programmable heating and cooling cycle lengths: 10, 12, 15, 20 or 30 minutes • Temperature display in °F or °C • Backlit display • Battery replacement indicator • Interchangeable faceplates (titanium, charcoal & taupe) 2. Installation 2.1 Removing the Old Thermostat IN ORDER TO AVOID ANY RISK OF ELECTRIC SHOCK, CUT POWER TO THE HEATING SYSTEM. n Remove the old thermostat to access the wires. Attention: If the old thermostat was mounted onto an electrical box, it was probably powered by 120/240 volts. In this case, this thermostat cannot be used. o Identify and label each wire (with the corresponding letter on the wire terminal) and remove them from the terminals. p If necessary, strip the end of each wire (maximum of 1/4 inch). p Tilt the thermostat upwards. q Mark and bore the appropriate mounting holes (using a 3/16" drill bit) or use the existing holes. Insert the plastic anchors. r Pass the wires through the opening of the baseplate and fix the baseplate to the wall using the screws provided. 2.3 Connecting the Thermostat Refer to the following table for matching the wire labels with the thermostat terminals. RTH1120 terminals Rh Rc W Y G Description Heating power supply Cooling power supply Heating signal Cooling signal Fan Wire labels Rh, R, 4, V Rc, R W, W1, H Y, Y1, M G, F Note: Do not connect wires identified as C, X or B. Wrap the bare end of these wires with electrical tape. Important: The red jumper wire between Rh and Rc terminals must be removed in a 5-wire installation. RTH1120 69-1875EF-1 29/11/06 1/4