Asked by: Piedades Orea
asked in category: General Last Updated: 29th May, 2020

What is a limit circuit lockout?

"Limit Circuit Lockout" when furnace seems to stop working. [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.

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Correspondingly, what does limit circuit open mean?

Usually an open limit is due to a airflow problem which causes the heater to heat up and trip a limit, do you have a clean air filter?? or it could be worse and the heater may have rolled out due to a bad heat exchanger, in either case, have a licensed repairman come out to look at the heater.

Also Know, what is 13 limit lockout carrier? 13 is limit circuit lockout, in which case your furnace would try and restart after 3 hours. The limit circuit is there to protect the furnace from overheating if there is insufficient airflow through the heat exchanger taking the heat away from the furnace and pushing it into your ductwork.

Keeping this in consideration, why does my limit switch keep tripping?

Like any other part in your HVAC system, the high limit switch can wear out over time. One of the most common issues that happens when a high limit switch goes bad is that it fails to signal the blower fan to turn off. High limit switches can also weaken over time so that they begin tripping at a lower temperature.

How do you know if a limit switch is bad?

One common symptom of a malfunctioning limit switch is a blower fan that doesn't shut off. This happens when the switch simply fails to shut off the fan after the burners have stopped and the air exchanger is sufficiently cool. A bad switch also can prevent a furnace from operating at all.

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