Why does my furnace shut off after a few seconds?

A common reason a furnace short cycles is because the heat exchanger, the part that heats your air, is getting too hot due to a lack of airflow. Once the heat exchanger overheats, it trips the high limit switch, which shuts the furnace down to protect it.

How long should furnace flame stay on?

Once you light the pilot, you need to keep the button depressed for at least 30 seconds (sometimes up to 1 minute). This gives the flame enough time to heat the flame sensor (thermocouple) that tells your furnace it’s OK to light the burner.

How often should your furnace kick on?

three to eight times per hour
On average, furnaces should kick on and turn off anywhere from three to eight times per hour. However, if your furnace turns on and off more frequently, don’t assume the furnace is short cycling just yet.

What happens when the main burner on a furnace ignites?

Problem: Your furnace main burner ignites, the main burner stays on for 8 to 10 seconds, then shuts right back off. Your furnace tries this ignition sequence again, and the same thing happens.

How are flat flame burners used in reheating furnaces?

The flat flame burners (FFB) are usually used on the roof of the reheating furnace. Due to these burners indirectly oriented radiant heat transfer takes place. The heat from fuel combustion is transferred to the steel charge material not only directly from the flame, but also through the roof refractory lining of the furnace.

What are the different types of furnace burners?

According to the position of the burners in the furnace, arrangements are classified into three heating methods namely (i) Use of axial-flow burners in front wall, (ii) use of side burners in side walls, and (ii) Use of flat flame radiant burners in the roof. Each heating method has its own characteristics.

Why do you need so many burners in a furnace?

Large burners produce longer flames, which is usually difficult to be contained within the furnace walls. Hence a large number of burners of lesser capacity are generally employed to ensure a better heat distribution inside the furnace and also to increase the furnace life.

Problem: Your furnace main burner ignites, the main burner stays on for 8 to 10 seconds, then shuts right back off. Your furnace tries this ignition sequence again, and the same thing happens.

Why does the flame stay lit for 10 seconds?

I have a Kenmore gas dryer model 110.76722690. The flame stays lit for 10 seconds or so and then shuts off. The duct work is clean. How would I replace the thermostat if that’s the problem?

What should I do if my furnace flame sensor goes out?

Clean your flame sensor with steel wool or emery cloth (fine sand paper). You might need a new flame sensor, but most of the time they can be cleaned and your furnace will work well after cleaning. I have seen the flame sensor go out. Most of the time when they go out the white porcelain is cracked.

What to do when your furnace goes into lockout?

After 3 times the furnace goes into lockout, and the only way to get it out of lockout is to turn the power switch off and on. Everything starts over again without ignition of your gas burners. Solution: First, turn off the power to your furnace.