Furnace temperature sensors play an important role in the safe operation of the heating system in your home, as they detect when there are impending risks of malfunction or danger and then enable preventive action. For example, the natural gas supply may be shut off to make the system shut down so as to prevent an explosion. Here are the common types of temperature sensors.
Thermocouple
Thermocouples are typically found in older models of gas furnaces that have a standing pilot. They comprise two dissimilar electrical conductors that form junctions at different temperatures. The voltage created by the temperature changes is converted to a temperature reading.
Thermocouples operate across a wide temperature range of about -450 degrees to 4,200 degrees. They’re less stable and less accurate than thermistors and resistance temperature detectors (RTD). Nevertheless, they’re widely used because of their small size, simple design, ease of use, and quick response to any temperature changes.
Thermistor
A thermistor, or thermally sensitive resistor, changes its physical appearance when exposed to temperature changes. Its temperature range is smaller, ranging from about -100 degrees to 500 degrees. The thermistor has a quick thermal response and very high sensitivity, which makes it work well over the limited temperature range.
RTD
Resistance temperature detectors are known for their good stability and high accuracy. They’re made of high-purity conducting metals, such as platinum, copper, or nickel. Their resistance changes with temperature changes. These sensors have a wide temperature range of about -400 degrees to 1,200 degrees. While they’re expensive and have a slower thermal response than a thermocouple, resistance temperature detectors have high precision.
The different furnace temperature sensors have different characteristics. If you need more information about furnace temperature sensors or any other HVAC components, contact the experienced technicians at Ace Hardware Home Services. Since 1972, we’ve proudly served the heating and cooling needs of satisfied clients in the Dayton area.
