Honeywell - CQ100A1013 - 24 in. L 0.03 V Millivolt Universal Thermocouple (2024)

FAQs

How do I know if my thermocouple is broken? ›

There's really just one telltale sign of letting you know when the thermocouple isn't working, and that's when the pilot light won't stay lit.

Universal thermocouples are commonly stocked for most models. It is important to verify that your model of water heater can utilize a universal thermocouple.

Replacing a thermocouple is a relatively easy fix that can take less than two hours. This guide reviews how to replace a thermocouple to ensure gas appliances stay in good working order, as well as how to relight a pilot light.

Common signs of a faulty thermocouple include inconsistent temperature readings, a pilot light that won't stay lit in a gas appliance, or a device that won't heat up. Remember, safety comes first!

A Dirty Thermocouple

As a result, the thermocouple can't properly detect heat, or loss thereof. When a malfunctioning thermocouple provides improper readings, it can shut off the gas supply to the furnace even when the pilot light is working.

Nothing lasts forever, and when the thermocouple wears out, the pilot won't stay lit and your appliance won't work. The pilot can go out for a number of other reasons, however, so if you're having trouble getting the pilot to stay lit, the thermocouple may not be at fault.

Problem: The most common error when connecting a thermocouple is that the polarity of the lead wires is reversed or altered. In this case, the measured temperature will be incorrect due to the temperature difference between the two ends of the leads.

Yes, you can clean a thermocouple, but the task must be done with a light touch. Remove the thermocouple from the process assembly, using a steel wool or emery cloth, lightly clean the tip removing any build up. Cleaning a thermocouple is not a fix for an issue, such as inaccurate readings.

Your first steps to select the correct thermocouple for you is to choose the application where the thermocouple will be used, research the temperature ranges the thermocouple will be exposed to, consider any chemical resistance needed for the thermocouple or sheath material, assess the need for abrasion and vibration ...

How much should a plumber charge to replace a thermocouple? ›

Having a thermocouple replaced usually costs $125-200, while the part itself is about $15-25. If a bad thermocouple isn't to blame for a nonfunctioning water heater, the gas control valve may be to blame.

Can a Water Heater Work Without a Thermocouple? Unfortunately, your water heater will not function properly without a thermocouple that is in excellent condition. As we mentioned earlier, when the thermocouple is not working, you won't have any hot water.

To figure out if your thermocouple is dirty, look at its tip. If you notice the tip is covered with a layer of soot, this means it needs to be cleaned as soon as possible. If you ignore this, you'll start having problems with the pilot light staying lit on a consistent basis.

Failed Thermocouple Symptoms

You are looking for a few things. The first is signs of contamination on the tube, which can include discoloration, cracks, or pinholes. Next, check the wiring for any signs of wear or corrosion like missing insulation or bare wire.

There is such a thing as too much heat for a thermocouple. Whether you accidentally use a thermocouple that isn't meant to operate at your applications temperatures or your processed run hotter than they should, exposure to overheating can damage the elements in a thermocouple.

Nothing lasts forever, and when the thermocouple wears out, the pilot won't stay lit and your appliance won't work. The pilot can go out for a number of other reasons, however, so if you're having trouble getting the pilot to stay lit, the thermocouple may not be at fault.

The thermocouple is what controls the unit's main gas valve. If the pilot is out or the thermocouple doesn't detect the heat from the pilot flame, the gas valve won't open and the unit won't ever turn on.

Symptoms Pilot won't light. Pilot lights but burner won't. System lights, but goes out after a while.

The thermocouple conductors of an MI cable can be contaminated after being exposed to demanding operating environments for a longer period of time. This will result in metal fatigue and changes in composition. Constant changes in temperatures can result in thermocouples to weaken over time and thus cause drifts.