“Are gas furnaces dangerous?” People often ask us this question, and the answer is a conditional “no.”
If gas furnaces posed major safety dangers, they would not be permitted in homes in the first place. A gas furnace can develop safety issues due to neglect and age, which is why we strongly recommend that our customers arrange for annual maintenance to keep their furnace in the best shape.
This gives us an opportunity to catch potential problems before they become problems. One of the reasons gas furnaces can operate at safe levels is because they’re constructed with several safety features to minimize risk. We’ll look at some of these features below.
The Limit Switch
This device is a temperature sensor located on the plenum of the furnace to monitor the furnace’s interior temperature. It serves several purposes.
Its primary job is to regulate the operation of the blower fan so that it turns on when the furnace’s heat exchanger has gotten hot enough, then shuts it off after the heat exchanger cools down.
As a safety device, the limit switch registers if the furnace’s heat exchanger is overheating (often because of a blower fan failure). If overheating occurs, the limit switch will shut off the furnace.
The Flame Roll-Out Switch
Flame roll-out is when the flames in the combustion chamber escape from the combustion chamber, often because of an oxygen deficit. Flame roll-out can damage the rest of the furnace and cause objects near to the furnace to catch fire.
The flame roll-out switch monitors the flames in the combustion chamber and automatically shuts off the gas to the burners in case of flame-roll out.
The Draft Pressure Switch
A gas furnace vents out toxic combustion gasses from the heat exchanger through a flue. A draft inducer fan draws these gasses up through the flue. Problems with the draft inducer or blockage in the flue can cause these gasses to flow the wrong direction, leaking out of the furnace and into the home.
The draft pressure switch monitors the pressure in the draft inducer to check that gas is moving the right direction. If it’s not, the switch will turn off the furnace.
The Flame Sensor
Once gas begins to flow to the burners, the ignition system ignites the gas. The flame sensor makes sure this process occurs, otherwise unburned gas will start to flood into the combustion chamber and create a major safety hazard.
If the flame sensor doesn’t detect that the burners have ignited, it will cut off the gas flow to the burners. (In older furnaces that use pilot lights, a device called a thermocouple does a similar job detecting flames.)
When it comes to furnaces in Courtenay, BC, Temprite Climate Solutions is the team to trust. We don’t just offer fast fixes. We help you understand the problem. We know how vital it is for your home to have a working heating system during our intense winters, and we’ll work hard to see you have a safe and effective gas furnace.
Temprite Climate Solutions serves Courtenay, BC and Surrounding Areas. For a job done right, call Temprite!