4 tips for thermostat maintenance

Your thermostat is Mission Control for your home's climatic comfort. Here are tips for keeping your home cool in summer and warm in winter, beyond moving the gauge. 

• The only way you're going to get the temperature in your home just to your liking is to make sure that the thermostat's thermometer is accurate.
• Every fall, before the heating season begins, do this simple test: Tape a household thermometer (one that you know is accurate) to the wall next to the thermostat. Give the thermometer about 15 minutes to settle on its temperature reading, and then compare that reading to the thermostat's.
• If the difference between the two is more than five degrees, recalibrate your thermostat.

•  A thermostat's heat anticipator tells it to shut off the furnace or boiler a little early, allowing residual heat to keep room temperature at the desired level.
• If your heating system cycles on and off too often (or not often enough), a few pokes at the anticipator ought to solve the problem.
• Access the inside of the thermostat and nudge the anticipator pointer toward a higher setting on its scale if the system is cycling too often; adjust the other way if it isn't cycling often enough.

• You've got to get at the guts of the thermostat to tune it. Start by removing its cover. Then, if you need to, unscrew the base plate containing the unit's working parts. Your thermostat's thermometer is usually a bi-metallic coil whose components expand or contract at different rates when they're heated or cooled. The flexing of the coil trips a switch (sometimes a mercury-filled glass bulb) that turns the system on or off.
• Recalibrating the thermometer usually involves turning the coil's adjustment screw or nut with a small screwdriver or needle-nose pliers. Double-check the manufacturer's instructions if you have them.

• The latest generation of thermostats offers extra customization and energy savings with seven-day programming, and an Energy Star-rated programmable thermostat can save you about $150 in heating costs per year. It doesn't take much time to replace an old mechanical thermostat with an electronic one; just make sure the new unit you select works on the same voltage as and is compatible with your HVAC system. (For some upgrades, you may have to have an electrician run new wiring.)
• Turn off power to your boiler, furnace, and/or air conditioner.
• Remove the old thermostat's cover, unscrew the front assembly, and disconnect its wires. Remove the front assembly; unscrew and remove the wall plate, if there is one. (Check with a local recycler about how best to dispose of the old thermostat, especially if it has a mercury switch.)
• If the wires aren't already colour-coded, tag them with the letters of the terminals to which they were attached. To keep the wires from slipping back into the access hole, secure them with a clothespin or tie them around a pencil.
• Slip the wires through the new thermostat's wall plate. Level the plate on the wall and mark the fastener hole locations. Use anchors and screws to secure the plate firmly to the wall.
• Follow the manufacturer's instructions to connect the wires to the new unit's terminal screws. Install backup batteries if necessary, and snap the thermostat onto the wall plate. Restore system power and program your new thermostat.