Clean Energy Springfield

You may be thinking about replacing an old wall-mounted thermostat with a programmable unit that will automatically adjust your home’s temperature settings while you’re away or sleeping. Electronic thermostats can help you save energy and save money on utility bills — when used properly, about $150 a year. They are better for the environment, since using less energy helps reduce greenhouse gas emissions associated with energy production.

But what about your old thermostat? Don’t just throw it away. It may contain mercury, especially if it is one of the round units. To see if your thermostat contains mercury, carefully remove the front cover to look for one or more glass bulbs containing a silver liquid. If you see this, you have a mercury-switch thermostat. These thermostats use mercury tilt switches containing on average 3 grams of mercury. While the device is operational and the mercury is enclosed, the thermostat does not pose a health risk, but mercury spills could arise if the thermostat is not handled and disposed of properly at the end of its life.

If you hire a licensed HVAC service technician to install your new, programmable thermostat, ask him/her if their firm is participating in a mercury-switch thermostat recycling program. If they are, see if they will take your old one for disposal. Also, you can dispose of mercury-containing thermostats at household hazardous waste collections that are periodically held in Springfield and other parts of the state. For a list of upcoming collection events, visit Illinois EPA’s web site or look for an announcement in your local newspaper.

If you choose to wait for a household hazardous waste collection, place the mercury-switch thermostat in a sealable plastic bag. Never remove the internal mercury switch from the thermostat. Use a sticker or some other form of identification to mark the bag “Mercury-containing item” and store the thermostat in a safe place away from children.