High Limit Switch Furnace Troubleshooting

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

High limit switch furnace troubleshooting.

Clogged furnace filter a dirty or clogged filter blocks the air flow into the furnace which may raise the inside temperature of the unit. 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. Limit switches turn off the burner and turn on the circulating fan if there is a high temperature condition in the furnace. 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. Fan control limit switch. As a working example we examine the honeywell combination fan and limit control type l4064b. The flames would raise the temperature inside the unit and have no place to go getting hotter and hotter.

This article describes in detail the testing and diagnosis of problems with warm air heating furnace combination controls also commonly called the fan limit switch on warm air heating systems. High limit switch a high limit control switch will turn off the gas to a furnace if the temperature becomes too high. 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. One way to keep your limit switch in good shape is to schedule a furnace tune up every year with jerry kelly.

How to check limit switches using your voltmeter. It also can shut down the furnace burners it if gets too hot inside the furnace. Next check the filter. The limit switch is a safety switch that monitors t.

A clogged air filter restricts airflow through the heat exchanger causing the furnace to overheat.