Thermocouple. If your furnace is an older model with a pilot light, it relies on a thermocouple to shut off its gas valve if the flame goes out. The average cost to repair or replace a thermocouple is
$100–$250
.
How long does it take to replace a thermocouple?
Thermocouples are designed to detect a pilot light’s loss of heat and close the gas valve to prevent a gas leak. Replacing a thermocouple is a relatively easy fix that can take
less than two hours
.
Can you replace furnace thermocouple?
What are the most expensive parts to replace on a furnace?
- Blower Motor and Capacitor: $500 – $1,500. …
- Draft Inducer Motor: $500 – $1,500. …
- Circuit Board: $500 – $1500. …
- Gas Valve: $400 – $1,000.
How much do thermocouples cost?
1 cause of pilot lights that won’t stay lit is a worn-out thermocouple. It’s easy to replace and a new one costs
$5 to $10
. Rather than trying to unfasten the thermocouple inside the water heater’s burning chamber, it’s easier to remove the whole burner and thermocouple assembly.
How do I know if my thermocouple is bad on my furnace?
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.
Does cleaning a thermocouple help?
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
.
What causes thermocouple to fail?
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.
Are furnace thermocouples universal?
Honeywell, White Rodgers, and other manufacturers make universal replacement thermocouples
, usually with a 30-millivolts (mV) rating for standing-pilot furnaces.
How long does a furnace thermocouple last?
In effect, new thermocouples were installed into contaminated tubes, causing the degradation of the sensors and generating greater than a 100°F shift in accuracy. In this scenario, thermocouple life, which should have been
close to one year
, was shortened to within a week.
Why does my pilot keep going out on my furnace?
A faulty, misaligned, dirty, or damaged thermocouple
is often the culprit behind your pilot light going out. The thermocouple is an automatic safety shutoff device that prevents the gas valve from opening if the pilot light is out.
Why is my pilot light not staying lit on my furnace?
If your pilot light won’t stay alight,
it might be the thermocouple
. Sometimes dust buildup collects on the thermocouple and blocks the sensor. Try cleaning the thermocouple and then relighting the pilot light. If it continues to go out, the thermocouple might need to be replaced.
How much is a new furnace for a 2000 square foot home?
For a 2,000-square-foot home, it’ll cost
around $3,300
for a new furnace based on total square footage and BTU rating.
Why are furnace repairs so expensive?
The number one reason why your furnace installation costs so much is because
you are paying for a long-term investment
. Like we mentioned earlier in this article, your furnace will last up to 15 years or more.
How long do furnaces usually last?
THE AVERAGE FURNACE LIFESPAN
A well-maintained furnace can last at least
15 to 20 years
, but completing annual maintenance and being diligent with repairs can extend its life even longer.
What happens if a thermocouple fails?
Normally when the thermocouple malfunctions or isn’t working, it simply
shuts off the gas to your heater
. This is important, particularly if the pilot light is out, because it prevents harmful gas from leaking into your home.
How do you check if a thermocouple is working?
How do you fix a thermocouple?
Will a pilot light stay lit with a bad thermocouple?
A thermocouple senses the heat of the pilot and allows gas to flow to the burner. A bad thermocouple will shut off gas to both the pilot and the burner so
the pilot light won’t stay lit
.
Can you bypass a thermocouple?
Realistically,
you have just disabled the thermocouple, but you can also reach in and unclip it from its holding bracket where it meets the pilot light
. In most cases it will be held on with a gravity clip, but some are held on with a screw that must be removed with a small screwdriver.
How do you clean a thermocouple on a furnace?
If you’ve tested the thermocouple, and the flame didn’t stay lit, then it’s time to clean it.
Carefully clean the end (sensor part) with a small wire brush, or ideally an emery cloth
. You can even use the end of a knife or smooth sand paper. Do not use liquid or soap of any kind.
What is the difference between a flame sensor and a thermocouple?
FLAME SENSOR VS.
Thermocouples are used on standing pilot furnaces that have pilot lights. The thermocouple sits near the pilot light and gauges whether it’s working properly, while the flame sensor detects that the burners are lit once they start to emit gas and the igniters light them up.
How do you fix a pilot light that keeps going out?
This is and easy fix, simply
let it cool down and brush off the dirt or debris
. Your thermocouple might bend. The end that sits near the pilot light flame is what communicates with the gas valve and tells it to open or close. If it is bent away from the flame it won’t register heat and will keep the gas valve closed.
Can I use sandpaper to clean a thermocouple?
Clean the thermocouple –
using the emery cloth sandpaper, sand the ends of the thermocouple and then give it a finishing touch with the lint-free cloth
. Hopefully, you can get to the ends of the thermocouple without having to detach it from the assembly, but you may have to do that.
