What can cause a flame roll out switch to trip?

What causes a flame rollout switch to trip?

  • Clogged exhaust vent. A clogged exhaust vent will restrict airflow through your heat exchanger.
  • Clogged heat changer. A clogged heat exchanger has the same effect as a clogged exhaust vent– airflow restriction.
  • Cracked heat exchanger.
  • Low gas pressure.

What is a limit switch lockout?

Limit switch response If the temperature is too high or the pressure too low, the limit switch will close, instructing the furnace to shut down and enter lockout mode. A dirty filter may also cause the limit switch to trip by reducing the air flow.

What does flame rollout limit switch do?

Furnaces have a safety component that will detect when a flame rollout occurs — the flame rollout switch. This switch stops the supply of gas to the furnace if the temperature outside the combustion chamber exceeds a certain level.

How do you fix a limit switch on a furnace?

You can try resetting the furnace limit switch yourself if you have a newer model by turning off the furnace for 30 seconds and then turning it back on. However, if this does not work or the furnace repeatedly shuts down, calling heating experts to reverse or reset the limit switch is a good idea.

What causes a limit circuit lockout?

[7] LIMIT CIRCUIT LOCKOUT — Lockout occurs if the limit or flame rollout switch is open longer than 3 minutes or 10 successive limit trips occured during high-heat. Control will auto-reset after 3 hours.

How do I know if my limit switch is bad on my furnace?

The most common sign of a malfunctioning limit switch is the continuous operation of your furnace’s blower. Just as the limit switch won’t allow the fan to turn on until the warm air has reached the right temperature, the limit switch also shuts down when the air cools to a certain temperature.