How to tell if you need a new furnace (and if you have an old furnace)

How to tell if you need a new furnace (and if you have an old furnace)

This is where a car analogy really works well. An old furnace that is on its last legs can cause you as much grief as a car that feels like it’s about to die any day now. And all kidding aside, an old gas furnace can be hazardous to you and your family. You know how this is going to end. Your old furnace won’t give out on one of the last bright, cool mornings in early spring. It will happen at 2:00 am in the middle of an Ottawa January night during one of our famous annual deep freezes. Also remember that in our city, we’ve got the furnace on for as much as eight months out of the year.

If only furnaces (and cars) had clear expiry dates like cheese or milk. They don’t so here are some of the warning signs you need to look for:

Your furnace is at least 15 years old
The average life expectancy of a gas furnace is 16-20 years. How can you tell how old your furnace is? It could be easy or require a bit of effort, depending on the model and when it was installed. Try one or more of these on your old furnace:

  • Remove the front panel and look on the inside for a sticker or plate that indicates the manufacturer’s date (if there isn’t a date but a serial number, make note of it and read on…
  • Turn the power off and check the fan – sometimes a serial number is stamped directly on the fan
  • Look for a tag or sticker that lists dates of when the furnace was serviced – the first date is often the installation date which will give you a close idea of when the unit was manufactured
  • Just call the manufacturer and give them the serial number

You see an increase in your gas bill
Like cars, furnaces depreciate over time and they naturally lose efficiency as they age. If the price per unit has remained the same and so has your usage, your furnace may not be as efficient anymore and is working harder to maintain the same level of comfort. Now you’re spending more for the same thing. In fact, it’s a double whammy: you’re spending more on fuel to keep your old furnace going while simultaneously losing out on the opportunity to save money by installing a new high-efficiency furnace.

You’re spending frequently on repairs
Do you sometimes feel like you’re putting your mechanic’s kids through college with your increasing visits to the garage? If you have had to call for service on your furnace more frequently over the past two years, you might need a new one soon. There’s a rule of thumb that says if you’re spending half of what it costs to buy a new furnace on repair bills, then it’s time to buy a new one.

Rust, cracks or excessive soot
An old furnace produces hazardous by-products — mainly carbon monoxide — that are normally vented safely out of the house. Check the unit for cracks or rust. Check the piping for cracks or rust. Check the floor for soot marks. If you see an increase in any of these, you need to call for professional service.

You’re feeling ill quite frequently
Carbon monoxide, if present, can leak undetected into your home. It is a gas that is odorless, colourless and tasteless. Frequent headaches, a burning feeling in the eyes or nose, nausea, disorientation can be symptoms. If this sounds familiar, open windows to air out your house and immediately call a gas service technician.

The burner flame is yellow instead of blue
You should be able to check the flame yourself by simply looking through a small window around the bottom of your furnace. If the flame is yellow, the furnace could be producing carbon monoxide.

There’s a change in the cycling pattern
If your furnace stays on longer or if it turns on and off more frequently than normal it could mean that some parts are failing and other parts are working harder to keep up the performance.

You hear strange noises
If you’re hearing noises you didn’t hear before — popping, squealing, rattling, banging — and they’re getting more frequent, some parts may be starting to go.

Your whole house isn’t comfortable
Are you starting to notice that you set your thermostat at your desired level but you still can’t get the house to feel right? Do you have an increase in cold and hot spots where there weren’t any before? These are telltale signs of an old furnace that just can’t cope with the demand anymore.

Listen to your old furnace – it will tell you when it’s time to retire

Your furnace is going to last a lot longer than your car but the life experience will be much the same. It will be great off the lot and for many years but eventually you’ll notice that things just aren’t working the same anymore. The key is to notice the signs early and take action sooner than later before a bad situation becomes worse.