What can damage a thermocouple?

A good thermocouple is going to be used, and that can lead to metal fatigue. Changes in temperature can cause regular expansion and contraction in metal, which will cause thermocouples to weaken over time. After enough time, metal fatigue can cause a thermocouple to break.

What are the symptoms of a bad thermocouple?

If you can’t get the flame to light at all, and you’re sure the gas is on, there’s probably an obstruction in the pilot tube. If the flame lights and goes out when you release the gas control knob after holding it in for the recommended 20 to 30 seconds, that’s the sign of a thermocouple malfunction.

How hot can a thermocouple get?

They are inexpensive, rugged, and can measure temperatures of several thousand degrees C. In fact, thermocouples and noncontact infrared pyrometers are the only devices available that can measure temperatures above 650°C.

What can cause a thermocouple to read high?

If your thermocouple is reading high, it could be because your sensor is located too close to a heat source. If your sensor is near a local heat source it could increase the temperature being measured as opposed to the position you wish to measure temperature.

What would happen if a thermocouple was overheated?

A: Thermocouples are designed to be low maintenance items. If the back end of your thermocouple bulb gets constantly overheated, it will fail. With excessive back pressure coming from the burner ports, thermocouples can get burned up quickly.

Can I bypass a thermocouple?

Can You Bypass Thermocouples on Patio Heaters? Constant heat supply ensures that your patio heater pilot light is lit at all times. If your unit is receiving no heat, this won’t be so. To temporarily sort the situation, you can bypass thermocouples until you have funds to replace them.

Do Thermopiles go bad?

Like the other component parts in your furnace, the thermocouple can wear down over time, producing lower voltage than it should when heated. And the worst part is that you can have a bad thermocouple without even knowing. Therefore, inspecting and testing your thermocouple should be part of your furnace maintenance.

How do you troubleshoot a thermocouple?

Place one test lead on the side of the thermocouple and the other to the end that screws into the gas valve. If the thermocouple has proper continuity, a small resistance reading should be visible on the multimeter. Many multimeters also indicate continuity with an audio alert.

How does a thermocouple act like a heat engine?

1, showing the heat flow due to phonon and photons, which carry heat from hot to cold by all possible routes (in parallel with the heat carried by the electrons). This always reduces the efficiency, so it should be minimized with suitable thermal insulation.

Can thermocouples measure negative temperature?

However, measurement errors can occur. Relatively inexpensive compared to other temperature measurement technologies, thermocouples are valued for their ability to measure a wide temperature range: from –200° to +1250°C (–328° to +2282°F). Thermocouples measure temperature differentials, not absolute temperatures.

Should thermocouple be in pilot flame?

The pilot flame should touch the thermocouple at a specific level. If the flame is blue and weak, and barely reaches the thermocouple, it needs to be stronger. If it extends well above the thermocouple, it’s too strong.