Why is my pilot on but no heat?

If there’s a pilot light, make sure that it’s lit and touches the thermocouple. If it’s lit but the burners don’t heat, feel the side of the furnace. If it’s cool, the problem might be the thermostat, gas valve or control board. Make sure that the gas valve is on and that there’s enough fuel.

Why is my furnace running but not kicking on?





Thermostat. If your furnace is not kicking on, it can be an issue with the thermostat. You should first make sure that the thermostat is switched to the heating function. Next, make sure that the temperature that you have the thermostat set on is lower than the temperature in the home.

Can hear your furnace click on but it does not fire up?

If your gas furnace initiates the start cycle but does not fire up, it’s likely because of a faulty, damaged, or dirty ignitor/sensor. This is a very common furnace problem—you can try to clean the sensor and replace the ignitor.

Why won’t my furnace burners light?

If your furnace won’t ignite, the source of the issue may be a broken flame sensor. The sensor is responsible for turning off the gas burners to avoid gas buildup. Once this component starts to malfunction, it may stop the burners from igniting altogether.

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 clean a furnace heat sensor?





Quote from the video:
Quote from Youtube video: So if you have a situation like this what you have 90% of the time is just a dirty flame sensor. So we'll go through the steps on how to clean it. So the right side of the furnace.

How do I make my furnace kick on?

What to Do When Your Furnace Won’t Turn On

  1. Check Your Circuit Breakers. Even if you use a gas or propane furnace, some of the components run on electricity. …
  2. Check Your Thermostat. …
  3. Check the Drain Pan. …
  4. Check Your Air Filter. …
  5. Check the Pilot Light. …
  6. Check Your Natural Gas or Oil Supply.


Why does it take so long for my furnace to kick on?

Your furnace might not turn on due to a burnt-out pilot light or a dirty flame sensor. A furnace may also be slow-starting because of an issue with its thermostat, so you may need to call in an electrician. Regardless, keep your furnace clean, and don’t forget to schedule an annual check-up before the winter season.

How long should it take for furnace to kick on?



five minutes

Your furnace should start up within five minutes of you turning on your thermostat.

How do I know if my ignitor is bad on my furnace?

Here are a few indications that you have a faulty ignitor.

  1. No Cold Air. …
  2. The Furnace Won’t Come On. …
  3. The Furnace Suddenly Stops Blowing. …
  4. Starts, Then Stops, Then Starts Again. …
  5. Tripping the Breaker More Than Once. …
  6. I Hear the Click, But Nothing Happens. …
  7. Flame Sensor Problems. …
  8. Short Circuit.

How do you test a flame sensor?



Quote from the video:
Quote from Youtube video: Then set your meter to measure. Microamps. As soon as the flame is established. You should see a microamp reading on your meter. My manual actually says i'm looking for between one and four microamps.

How do you tell if an igniter on a gas furnace is working?

Quote from the video:
Quote from Youtube video: If your gas furnace uses a glow bar style igniter. You can often determine that the igniter has burned out if the filament appears singed or cracked.

How do I know if my thermocouple is bad on my furnace?

A bad thermocouple itself can prevent a gas furnace or boiler from working – if you can light the flame at the pilot manually but then the flame goes out when you release the manual gas feed valve, the thermocouple is probably bad.

How do you test a thermocouple on a furnace?

Take the two leads from the meter and touch them—the meter should read zero. Once this check is done, turn the meter back to volts. For the actual test, turn on your flame source, and place the tip of the thermocouple into the flame, leaving it there until it is quite hot.

How much does it cost to fix a thermocouple?



Thermocouple – $20 to $150



The thermocouple is an apparatus that senses whether the pilot light is lit and triggers the gas control valve. Repairs typically cost about $150 to have it done professionally, though a new thermocouple itself only costs about $20 on average.

Why is the furnace blowing cold air?

If your furnace is blowing cold air in your home, this is a sign of an issue with the flame detector, gas supply, air filter, pilot light, or condensate lines. Many of these issues are able to be easily solved on your own by sanitizing or replacing components in the gas furnace.

How do I reset my electronic ignition furnace?

How to Reset an Electric Furnace

  1. First, turn off the power supply to the furnace by turning off the breaker in the circuit box.
  2. Locate the reset button on the furnace and press it to reset the furnace. …
  3. If the button is popped up, press it down.
  4. Return the cover to the blower compartment and turn the power on.


What does a furnace thermocouple look like?



Quote from the video:
Quote from Youtube video: And will ignite the main burner when heat is needed the thermocouple is a safety device that monitors the pilot. Light heated it creates voltage which opens the gas valve only when it's safe to burn.

Is a flame sensor for the pilot light?

If you have a furnace with an electronic controller, it will have a flame sensor. If you have a furnace that uses a standing pilot light that’s continuously lit, you will have a thermocouple. This component is located next to the pilot light, and it monitors how that component is performing.

What are the symptoms of a bad flame sensor on a furnace?

6 Signs of a Malfunctioning Gas Furnace Flame Sensor

  • Yellow Burner Flames. Open up or glance through the peephole of your gas furnace to see the color of the flames firing up in the burner. …
  • Rusted Flue Lines. …
  • High Utility Bills. …
  • Water Leaks. …
  • Old Age. …
  • Constant Thermostat Adjustments.


How do you troubleshoot a flame sensor?

How do I know if my furnace flame sensor is bad?

  1. Switch off the power to your furnace.
  2. Close the gas valve.
  3. Take out the mounting screw.
  4. Carefully pull out the sensor.
  5. Inspect the sensor: if the insulation is intact but appears sooty, burnt or slightly corroded, it might only require cleaning.

How often does a flame sensor need to be replaced?

Flame sensor lifespan



If you’ve just replaced the sensor or had a new furnace installed, you can expect the flame sensor to last for about five years. The average lifespan of a furnace is 15 to 30 years, so you can anticipate a flame sensor replacement once or twice over the course of your homeownership.

How much does it cost to replace a furnace flame sensor?

Flame Sensor



It stops your furnace from letting off large amounts of natural gas if it’s not working properly. If the sensor is bad, it won’t be able to sense heat and will turn the furnace off. The average cost to repair or replace a flame sensor is between $75–$200.

Is it safe to clean a flame sensor?

Quote from the video:
Quote from Youtube video: You know remove it to sensor itself from the wire. Clean. It off with your steel wall or your knife and then replace it make sure everything is back in place.