If you have a gas furnace as many of us do in Oklahoma, you have a heat exchanger. This portion of your heating system is heated by the open flame that is inside your unit. It is porous, allowing air to pass through it, similar to a radiator. Cool air passes through it is heated by the heat exchanger and then passed along to your vents. I think just about everyone has had to relight their pilot light at one point or another because the air coming out of their vents was cold. That pilot light is what ignites the furnace portion and heats the exchanger.
Sometimes the heat exchanger cracks or even rusts with age. Newer units have safety mechanisms in place that account for this, but it's usually the older units that time is catching up to. Many of these units predate current safety mechanisms to account for heat exchanger issues.
What can happen from a faulty heat exchanger?
First, a cracked exchanger can allow the exhaust gases from your open flame to mix with the air passing through the exchanger. This ultimately leads to carbon monoxide, an odorless killer, blowing out your vents. If left unchecked, the exchanger can actually leak enough carbon monoxide to be deadly.
Second, the heat exchanger can have air pulse back through to the burner, causing a flame rollout. We are called out on no less than 3-5 instances per season of flame rollout. This is a major fire hazard and a good reason to be careful of what you store next to your furnace. Any flammable substance only increases your risk.
How can I check to determine the health of my gas furnace?
Damaged heat exchangers are difficult to detect. There are carbon monoxide tests, but often it will take a scope to detect the problem. We always recommend that you have a qualified company perform the inspection. As a reminder, our Maintenance Plans offer seasonal inspections of both your heating and cooling. Many of our clients sleep easily knowing that everything is in order and their families are safe.