There are at least 2 heat exchangers in a high efficiency furnace- one primary and one secondary. These parts are same as the backyard fire ring which is used to contain the embers, wood and flames. It is like a metal pipe with one end working as an inlet and the other working as an outlet. Flames enter the heat exchanger from one side and leave through the other. The key role of the heat exchanger is what it’s name suggests: it exchanges heat from the burning gas to the surrounding air that moves through it from inside your home. It separates exhaust fumes from the inside air of your abode at the time of combustion process. Heat exchangers stop working when they get cracked and thus replacement is required.
Limit control is one more safety control mainly responsible with turning off the combustion process in case the indoor blower motor stops working. This ensures that the heat exchanger doesn’t overheat due to deficiency of air over the heat exchanger due to broken indoor blower or clogged filter.
It is responsible for moving air through the furnace. Sounds you may hear is because of this action.
These are safety switches that shut down the combustion process automatically if they find fire where it is not supposed to be. Usually, this happens if the vent fan stops working or the vent pipe gets clogged.
A vent fan, as name suggests, is responsible for venting fumes out of the heat exchanger and into the PVC pipe that sends the fumes out. If vent fan is damaged, the automatic pressure control would notice the loss of pressure and stop the combustion process.
Pressure switches are safety devices that continuously check the internal pressure of the combustion area. If there are issues in the vent fan, vent pipe, or heat exchanger, the pressure switch cuts the power to the automatic gas valve.
These gas valves are components in the furnace that close and open automatically and allow unburned propane or natural gas into the heat exchanger. The automatic gas valve opens when the furnace gets a signal from thermostat for a heat cycle and all other safety conditions are sufficed, thus allowing gas to flow. Gas is then sent to a device called burner where it is combusted and sent to the heat exchanger.
Do you suspect one of these parts is in need of repair in your furnace? Contact the experts at Romaniuk Heating & Air Conditioning today for an assessment!