Thermostats with mercury will have the “Hg” sign for mercury on the packaging. Most thermostats sold today don't contain mercury . Programmable electronic thermostats and many manual thermostats are now mercury-free.
When did they stop using mercury in thermostats?
manufacturers in the U.S. – General Electric, Honeywell, and White-Rodgers. These companies reported that they phased-out the manufacture and sale of mercury-added thermostats in October 2009 . Since 2001, many states have passed legislation restricting the sale of mercury-added thermostats.
Do they still use mercury in thermostats?
Are thermostats dangerous? Many thermostats use mercury switches, but as long as a thermostat is intact, it isn't dangerous. Electronic and magnetic snap switch thermostats don't contain any mercury . ... When they must be replaced, discarded mercury switch thermostats become “universal waste”.
How do thermostats work without mercury?
The mechanical contact thermostat uses a simple mechanical contact instead of a mercury contact switch. Like a mercury contact thermostat, a mechanical thermostat uses a bimetallic coil (to open or close the mechanical contact points) and includes a heat anticipator.
Is there an alternative to using a thermostat containing mercury?
Alternatives to Mercury-Containing Thermostats
Electronic thermostats, which are mercury-free, are available. The best alternative is to use what are called programmable thermostats . These thermostats can be programmed to keep the temperature of a house a certain level depending on the time of day and the season.
Should I replace mercury thermostat?
Myth:Mercury-bulb thermostats should be replaced because they are inaccurate . Fact:Mercury bulb thermostats are among the most accurate for temperature control within the HVAC industry. Cheap electronic thermostats provide inferior temperature control. Myth:Mercury bulb thermostats are hazardous and should be removed.
How do I know if my mercury thermostat is bad?
There should be an open circuit when the mercury is not contacting the wire contacts and a closed connection when it is. If the thermostat fails either of these simple checks, it is defective. The easiest way to check thermostat function is to jump across the terminal screws with a jumper wire .
How long do mercury thermostats last?
Although a mercury filled thermostat may last 20 years , or more, the mechanical parts begin to wear out long before that, becoming less accurate and therefore less efficient over time.
Can you replace a mercury thermostat with a digital?
Sometimes you have to flip the switch on the back of the thermostats depending on which type of system you have. If you're going from mercury to a modern age digital thermostat the process can be simple if you just watch what you're doing to pay attention.
What do I do with my old thermostat?
So, what should you do? Place your old thermostat in a sealable container such as a ziplock bag or plastic tuperware container. This is so that if the mercury bulb breaks inside the device, its vapors will not be breathed in. Check online for the nearest hazardous materials drop-off site.
How do you know a thermostat is bad?
HVAC system won't turn on : The most obvious sign of a bad thermostat is that the HVAC system in your building won't turn on or respond to the thermostat. You should be able to turn on your heating or cooling system from the thermostat, or change operation back and forth from heating to cooling.
Are digital thermostats better than mercury?
Thermostats are a vital component of any air conditioning system. Without a thermostat, the air handler will not be able to respond accurately to the cooling requirements for your home. ... A digital thermostat is also a far better option than an older style mercury thermostat for three very good reasons.
How much mercury is in an old thermostat?
A mercury thermostat holds 3 to 12 grams of elemental mercury – it's typically the largest source of mercury in homes. The mercury within a thermostat is much like the materials inside a compact fluorescent lightbulb (CFL) – it's safe as long as it's contained.
What do thermometers use instead of mercury?
Ethanol-filled thermometers are used in preference to mercury for meteorological measurements of minimum temperatures and can be used down to −70 °C (−94 °F). The physical limitation of the ability of a thermometer to measure low temperature is the freezing point of the liquid used.
How does an old mercury thermostat work?
Mercury thermostats contain bimetal coils that contract and expand with room temperature. When the coil contracts or expands, it activates the mercury switch , which opens or closes a circuit to make the furnace, heat pump, or air conditioner turn on or off.
What are alternatives to mercury thermometers?
There are numerous alternatives to mercury thermometers. But increasingly, selecting an alternative to Hg is chiefly a matter of choosing among one of the three sensor types used in digital thermometry: platinum resistance (PRT), thermistor, and thermocouple .
