How Do I Know When to Replace My Furnace?
If you live in the northern hemisphere, winter can be an uncomfortable time of year. It would help if you kept your home warm, so you don’t have to scrape together money for a motel room because your heating system has decided not to work.
Do you know when it’s time to call the professionals? How do you do if you should replace your furnace before it goes out on you again during another cold night?
Before answering that question, let’s look at how furnaces work and why they might break down.
How Does a Furnace Work?
The primary task of a home furnace is to heat air using gas or electric resistance coils inside the unit. Air rises through ducts throughout your house, and warm air replaces the cold. This process is called convection.
In a furnace with an electric heating coil, a fan blows air across that coil to disperse heat into your house. If this blower stops working, you might have to get up on a step ladder and turn it back on by hand.
Gas furnaces use a combustion process to generate heat between the flames inside the furnace chamber and the metal of the heating coils. Coal or oil is burned to create gas, which is usually routed through either ceramic brick material or thin slats under high pressure so it can produce its flame against those coils when lit by an ignition button at the base of the furnace near your thermostat. In older models, this flame will need to be adjusted manually via a gas valve on the side of your furnace. However, many models are automatic now.
These furnaces use blowers to circulate air heated by the coils throughout your house. This fan might have one or more speeds that can be set with a dial near your thermostat. The speed of this fan is usually controlled using another dial inside the blower compartment, which you’ll need to get into if it breaks down and stops working.
A potentially significant problem with older furnaces is that they may lose oxygen over time as old filters clog up and stop allowing enough airflow through them — significantly if you don’t change those filters on time every month during every season. This insufficient airflow can cause a furnace to malfunction, and it may even damage your blower fan. If you see the flames diminishing inside your furnace chamber over time, that’s usually an indication that not enough air is reaching your heating coils.
Many other components inside furnaces might fail with age, including pressure switches, pilot lights, gas control valves, thermostats, temperature sensors, and more — all of which are designed to monitor whether everything in the system is working correctly or not.
Let’s turn to some statistics now . . . At what point do all these smaller parts wear out? When does it make sense to replace your entire furnace rather than pay for pricey repairs?