Asked by: Teodolinda Hessler
home and garden smart home

Are mercury thermostats accurate?

Last Updated: 27th February, 2020

20
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 should be removed from a thermostat when the thermostat is replaced.

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Keeping this in consideration, what replaced mercury in thermostats?

There are certainly still thermostats around with Mercury switches attached to bi-metal coils, but they have been replaced with electronic devices with an electronic sensor, a bit of digital logic, and either a solid state or mechanical relay.

Subsequently, question is, is mercury still used in thermostats? 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.

Hereof, how do I know if my mercury thermostat is bad?

Remove the thermostat cover and look at the mercury bulb while turning the dial; the bulb should rotate as the dial is turned. The drop of mercury should move and make contact with the wire contacts as the temperature selector is turned up.

How long do mercury thermostats last?

20 years

Related Question Answers

Merlyn Galeotti

Professional

When did they stop putting mercury in thermostats?

A growing number of states have banned their sale. Washington state instituted such a ban in 2006. Three major thermostat manufacturers — Honeywell, General Electric and White-Rogers — have stopped making devices with mercury switches.

Chrystal Vertiev

Professional

What states are mercury thermostats illegal?

There are 12 states where it is illegal to dispose of a mercury thermostat any other way than by recycling: California, Iowa, Illinois, Maine, Massachusetts, Minnesota, New York, New Hampshire, Oregon, Rhode Island, Pennsylvania, Vermont.

Ieltxu Maravilha

Professional

Is thermostat mercury 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. Each tilt switch contains roughly 3 to 6 grams of mercury.

Cabeza Probal

Explainer

Can you replace a mercury thermostat with a digital?

Keeping track of what wire originally went where is very important when installing the new thermostat. Mercury thermostats are really “old school” and most have already been replaced with either newer mechanical models or digital ones.

Alvera Troepolsky

Explainer

Are mercury thermostats illegal?

Recycling mercury thermostats can be expensive because they are considered hazardous waste; the expense can lead to their illegal disposal, or lack of disposal. HVAC contractors are required by law to recycle all mercury thermostats they remove. In eight states, mercury thermostats are banned from being installed.

Konstantine Filu

Pundit

How much mercury is in a thermostat?

According to the Thermostat Recycling Corporation (TRC), mercury thermostats contain an average of 1.4 mercury switches (i.e., components), with a minimum of 2.8 grams of elemental mercury per switch. Therefore, the total amount of mercury used in a thermostat is approximately four grams.

Natalja Mommer

Pundit

What type of mercury is in thermostats?

If a thermostat uses a dial or lever, it likely contains 2 to 4 grams of mercury. Common mercury-containing brands are Honeywell and White-Rodgers. If you want to upgrade your old, mercury-containing thermostat, ask your contractor about your HVAC system's needs to make sure you get the right device for your home.

Detelina Iznardi

Pundit

Does low battery affect thermostat?

Most models of programmable thermostats will display or flash some sort of low battery symbol when the batteries begin to run low. At this point, the thermostat can no longer control the HVAC system. This could possibly lead to excessive heating or cooling of your home, or no heating or cooling at all.

Encarna Bosio

Pundit

How do I know if my thermostat is broken?

The most common signs of a broken thermostat are:
  1. Thermostat display is off or is non-responsive.
  2. Turning on the heat or AC does nothing.
  3. The heat or AC will come on, but either stays on nonstop or cuts out before the temperature setting is reached.

Majid Peerlings

Pundit

How do you troubleshoot a thermostat?

You can successfully troubleshoot a thermostat.
  1. Check the thermostat temperatures. There are two temperatures to take into consideration when dealing with a thermostat; set point temperature and room temperature.
  2. Calibrate your room temperature.
  3. Check the connections.
  4. Take the thermostat out of the equation.

Geoffrey Legaz

Teacher

Can a thermostat cause short cycling?

Thermostat Troubles Can Cause Short Cycling
Your thermostat could also cause the HVAC system to cycle on and off rapidly, a process known as short cycling.

Zarai Eicken

Teacher

How do you know if you need a new thermostat?

In most cases, the thermostat will produce a small clicking sound when the changes are made, then the heating or cooling equipment will start. If this clicking sound doesn't occur, or if the system doesn't come on shortly after the changes are made, the thermostat may need replacing.

Adib Corona

Teacher

How do I test my thermostat?

Checking your car's thermostat
  1. Have your car on level ground and make sure the engine and radiator are cool.
  2. Open the car hood and find the thermostat.
  3. Next, you will need to test your car thermostat.
  4. If you find the coolant is flowing, it means the thermostat valve is open.

Nelia Lobenhofer

Teacher

Why is my thermostat reading the wrong temperature?

Perhaps the most common cause of a thermostat reading the wrong temperature is that it is not located in the most optimal place within your home. If your thermostat is in direct sunlight, near sources of heat or drafts, or not centrally-located within your home, it will not give an accurate temperature reading.

Dominique Vieillard

Reviewer

How do I reset my thermostat?

Here are the steps you need to take to reset your AC thermostat.
  1. Shut Down Your AC at the Thermostat. The first step in resetting your AC thermostat is to turn it off at the AC unit.
  2. Find Your Circuit Breaker Box.
  3. Reset the Circuit Breaker for Your AC Unit.
  4. Wait 30 Seconds.
  5. Turn the AC Thermostat Back On.

Cresencia Friedenson

Reviewer

Are WIFI thermostats worth it?

You Won't Use It — Even though the benefits sound fun, you need to actually use the technology to get any benefit from it. If you neglect the smart functionality and just use your new thermostat on the wall, a wi-fi thermostat probably won't be worth it for you.

Eumenio Gschopf

Reviewer

What do you do with a mercury thermostat?

Mercury-containing thermostats
If your thermostat contains mercury, it is incredibly important that you dispose of it properly. It can be toxic if you throw your thermostat in the garbage and the vial containing mercury breaks and leaks. If recovered properly, mercury causes no environmental harm and can be recycled.

Azize Arede

Reviewer

Why is mercury dangerous?

This liquid form of mercury is especially dangerous because it vaporizes at room temperature. If mercury vapor is inhaled, it is easily absorbed by the body, where it first gets into the lungs and from there into the blood and the brain. The nerve poison can cause sleep disorders, agitation, and paralysis.

Wenting Brenneis

Supporter

How do I adjust my thermostat?

Set the thermostat's system switch to the right, or 'Heat,' setting if the unit is fitted with a sub base. Adjust the thermostat dial until the setting exceeds room temperature; the system should start blowing hot air. Adjust the dial to below original room temperature; the heating system should stop blowing hot air.