High Limit Switch Furnace Troubleshooting

The high temperature limit switch senses the temperature of a furnace and tells the blower fan to turn on and off at the appropriate times.

High limit switch furnace troubleshooting.

As a working example we examine the honeywell combination fan and limit control type l4064b. Clogged furnace filter a dirty or clogged filter blocks the air flow into the furnace which may raise the inside temperature of the unit. Fan control limit switch. Limit switches turn off the burner and turn on the circulating fan if there is a high temperature condition in the furnace.

Flip the switch on the side of your furnace and flip the breaker off and on again before you even think about replacing any parts. If the furnace failure code indicates an open limit or open high temperature switch or open rollout switch it is probable that the furnace has overheated. In this episode of repair and replace vance shows how to replace the high limit switch in a gas furnace. When the temperature gets too high the high limit switch turns off the gas to the furnace.

During your tune up not only will we inspect your limit switch but we will also take care of airflow issues with your system that can cause your limit switch to break down. A clogged air filter restricts airflow through the heat exchanger causing the furnace to overheat. The flames would raise the temperature inside the unit and have no place to go getting hotter and hotter. It also can shut down the furnace burners it if gets too hot inside the furnace.

High limit switch a high limit control switch will turn off the gas to a furnace if the temperature becomes too high. One way to keep your limit switch in good shape is to schedule a furnace tune up every year with jerry kelly. Next check the filter. The limit switch is a safety switch that monitors t.

For example if the blower motor stopped running then no air would move through the unit.