If your HVAC contractor or utility company has red-tagged your furnace, operating it could prove hazardous to your health. While there are many problems that can put a furnace out of commission, a cracked heat exchanger is one of the most common.

In the heat exchanger, the furnace burns fuel, turning it into usable heat energy that can be transferred to the air in your home. In furnaces that haven’t received regular maintenance or have been allowed to accumulate layers of dirt, the system may overheat, which can lead to cracks. But heat exchangers simply grow more prone to cracks with age, too, as the years of contraction and expansion due to temperature changes take their toll on the metal. Cracked heat exchangers can release carbon monoxide into the house, making them very risky to operate.

Red-tag furnaces may be disconnected from the gas supply or just shut down and unplugged. If this happens, don’t try to run the heating system. Use space heaters to keep warm. A fireplace, kerosene heater or propane heaters can help, but make sure your living space is ventilated. Protect your pipes to prevent freezing and bursting by consulting with your plumber as to the best course of action.

From here, you may have a couple of options:

Replacing the heat exchanger may be a viable course of action. Like an A/C’s compressor, the heat exchanger is the core of the furnace. Be aware that replacing it can be pricey if the part isn’t covered by warranty. It’s also a labor-intensive job.
Because heat exchangers can be expensive to replace, many homeowners with red-tag furnaces choose to invest in a whole new furnace instead. It doesn’t always make sense to install a new heat exchanger in an old red-tag furnace, especially if your furnace is seven to 10 years or older- especially if it is out of warranty. Often even if the furnace is in warranty, you can get the value of the warranty heat exchanger applied to the cost of a new furnace instead.

Red-tag systems are not only inconvenient, they’re potentially dangerous. If you find yourself saddled with a red-tag furnace, contact P.K. Wadsworth. We’ll be happy to verify the diagnosis so that you are assured you are getting the best advice. We will thoroughly review all your options with you and will recommend the safest, more cost-effective course of action to keep your family comfortable.