How do I check a mercury thermostat to see if it is a switch?

Mercury switch thermostats are not available for purchase in many states.It is important to properly dispose of the thermostats that contain mercury if they are changed out for newer digital thermostats.Many homes and businesses still use these thermostats, so we will give a brief description of how they work.

Zone valves and boiler controls are other uses for mercury bulb thermostats.The same way as air conditioning and heating thermostats, these thermostats control different functions for heating applications.

Mercury is a liquid metal.Mercury is hazardous to the environment and human health.Millions of people used mercury type thermostats for heating and cooling.

The switch mechanism that closes contacts in a mercury thermostat is what the mercury bulb and contacts are.The mercury bulb is connected to a strip.The bi-metal strip in a thermostat is made of two different metals and has a calculated reaction to temperature.

When it gets hot and cold, the bi-metal strip expands and contracts in a spiral.That causes the mercury bulb to move.The thermostat tilts the mercury bulb in one direction or the other depending on the temperature.The mercury slides in the bulb to complete the circuit when the thermostat is set to heat and the temperature is cold.

As the temperature warms, the bi-metal reacts to the warming and causes the mercury bulb to tilt and break the circuit on a call for heat.The same sequence happens on a call for air conditioning except for the mercury in bulb completes the circuit on different set of contacts which control the airconditioning or heating system.

When the mercury thermostat is replaced by another thermostat, it is important to dispose of it properly.Care is not taken in the disposal of mercury, which is a very toxic metal.Water purity, wildlife, and even the health of humans are affected by that.Call your local department to find out if they have a thermostat supplier.They usually have programs in place to make sure that the thermostats are not thrown away.

The ultimate guide to creating a comfortable, healthy, long lasting, and efficient home is the Home Comfort Book.

What does the small metal circle in the middle do?What does changing the arrow do?

To turn the fan on when the heat exchanger reaches a specific temperature, change the high limit setting.It should be set according to manufacturer recommendations.

In the case of 347v baseboard heaters, is the murcury switch in the thermostat disrupting the line voltage or just a control circuit that switches off and on?

There is a possibility of a control circuit.Make sure the switch is rated for the correct amount of power.

I have a thermostat for heat only.I am trying to save it after my roomie messed it up.

Is it possible to pull the dial out to expose the workings?I don't know if I have to loosen the screws to take it apart.I want to jump it.

The thermostat needs to be removed from the sub-base.If the glass bulb with mercury inside is broken, you need to replace it and be careful with the clean-up.?