Unfortunately, heat exchangers usually require expensive repair, but that may often be the only alternative to completely replacing the furnace. The limit switch detects heat and tells the blower ...

Every furnace has a high-limit cutoff switch which turns off the unit if ... Filters are easy to replace. Do it monthly to keep your furnace in top form. The control board is full of sensitive ...

The "high limit" switch controlled by the thermostat mounted inside the furnace is designed to prevent this, and will shut off gas to the burners if the thermostat in the plenum reaches its preset ...