Before attempting to install the thermostat, read the manufacturer’s installation instructions for full details and any special instructions specific to the device. These instructions should be followed as closely as possible to ensure efficient thermostat operation.
Always handle the device carefully, as rough handling may decrease the thermostats accuracy. Inspect the thermostat carefully when you unpack it to make sure the shipping did not damage the device. The thermostat is the basic controller in any heating and cooling system so it is crucial it operates accurately and efficiently.
Make sure the thermostat selected for the heating and cooling system is the appropriate one for the job. Heat pumps require two-stage thermostats. Furnaces and boilers used with air conditioning systems commonly require thermostats with extra terminals. Thermostats with changeover terminals are required for many zoned systems. Check the manufacturer’s specification sheet before making a final selection.
Each device will have special instructions with its installations but these are six steps that will be common to all:
- Mercury-switch thermostats are usually shipped with some form of protection around the mercury tube to prevent breakage. This must be removed before operating your thermostat.
- You need to disconnect the power supply before connecting the wiring to your thermostat so you don’t run the risk of getting an electrical shock. This will also help prevent any damage to the equipment when wiring. Low-voltage thermostats are used in most HVAC systems. These low voltages are not fatal but can deliver a nasty shock that could hurt you or the system controls.
- All of the wiring must be connected in order as the directions say. If you are concerned with a the wiring, you can lean to help from a local electrician.
- Use a plumb line or spirit level to accurately level the sub-base or wall plate when mounting it on the wall. Thermostat controls deviations are often caused by inaccurate leveling.
- Check out the installation to make sure the thermostat is operating correctly.
Low-voltage room thermostats are recommended over the line voltage types for residential heating and cooling systems. The low-voltage thermostats respond more quickly to temperature change and will maintain the temperature and humidity more closely than the line voltage types. A low-voltage thermostat requires the use of a transformer to reduce the line voltage for the control circuit but the cost of the transformer is more than offset by the lower installation cost.