Hyderabadghar/Do it your self/Replacing a Thermostat

A thermostat needs less than 120 volts of power to operate; the circuit on which it is installed uses a transformer to step down the house voltage to 12 or 24 volts. When replacing a thermostat, choose one that is compatible with your system. Since thermostats vary considerably from one to another, be sure to get full installation and programming instructions with the unit when you buy it. Use the instructions here as a guideline while following the recommendations of the manufacturer.

PROJECT BASICS

Project: Easy
Estimated Project Time: Half-hour
Start Tips: Make sure that the replacement thermostat is compatible with your system
Safety Tips: Before starting to work, turn off electrical power to the circuit you will be working on
Recommendation: Do-it-Yourself

TOOLS & MATERIALS

thermostat	Spirit level
Screwdriver	Wall anchors, as needed
Pen	Power drill and bits, as needed
Masking tape	Hammer, as needed
Combination tool	Long-nose pliers
Utility knife

Make notes of Terminal Location and Code Identification

Fig. 1

INSTRUCTIONS

1) Remove the old thermostat
Carefully loosen the cover of the old thermostat from its base plate and gently pull it away from the wall. Disconnect the wires from the old thermostat. As you disconnect each wire, make note of its terminal location and code identification. Wrap masking tape around the end of each wire and use a pen to record the information. (Fig. 1) Then remove the base plate from the wall. If its edges are sealed to the wall by layers of paint, use a utility knife to score through the paint before removing it.

Use Base Plate as Template for Marking Holes Position

Fig. 2

2) Install the base of the new thermostat
Install the base of the new thermostat in the same location as the old base (preferably away from heat sources), gently pulling the tagged wires through to the front of the new base. Be careful not to damage the wires or pull off the labels on them. To install the new base, you may need to first install wall anchors in positions to match the mounting holes of the new base. Use the base plate as a template for marking the position of the holes; first make sure it is level. (Fig. 2)

Fig. 3

3) Attach new thermostat
Attach each of the old wires, one at a time, to the corresponding terminals of the new thermostat. Before you attach each, remove its label, and if necessary, strip and clean the wire end. Finish by installing the new faceplate. (Fig. 3)