Licensed certified gas technicians are legally obligated to red-tag any appliance they discover in a state deemed "unacceptable." They possess the authority to assess whether a furnace or any other appliance warrants a red tag, and if so, to determine the appropriate type of tag .
What constitutes an "unacceptable condition"? If your furnace or water heater has been red-tagged, it may be due to the following reasons:
- Damage or deterioration that compromises its safe operation.
- Issues with the condition of its piping, tubing, or hoses.
- Usage for a purpose not approved for it.
- Alterations that jeopardize its safe operation.
For residential heating appliances, options A or B are typically the primary concerns. It's unlikely that you've tampered with your equipment or used it for unconventional purposes. Regardless, you need not speculate, as the tag will specify the reason for the red tagging (and a competent technician should have provided an explanation.)
With furnaces, a cracked heat exchanger is among the most frequent causes for red tagging. The heat exchanger facilitates the transfer of heat energy to circulating air while safely containing combustion by-products. When it develops cracks, there's a risk of those by-products, such as carbon monoxide, leaking.
Subsequent steps depend on the type of red tag issued.