If you’re like most Wisconsinites, you rely on gas-fired appliances such as your furnace and water heater every day. When these systems are installed by a reputable contractor, they’re designed to meet the safety standards in place at the time of installation.
But as our understanding of safety evolves, so do building codes and industry best practices. To learn more about today’s recommendations for venting systems, we spoke with Carlos Albelo of IPEX USA about UL 1738, the standard that helps ensure venting materials are suitable for safely carrying combustion gases from gas-fired appliances.
Summary
- Many homes use white PVC pipe to vent gas-fired appliances, even though standard plumbing PVC was not specifically developed or tested for venting combustion gases.
- UL 1738-certified venting systems are designed and tested specifically for gas appliance venting and can help improve safety and compliance with current industry standards.
- UL 1738-certified venting systems are already required for many commercial installations under applicable building codes.
- As building codes continue to evolve, UL 1738-certified venting systems are expected to become more common for new residential installations.
- If you’re replacing your furnace or water heater or completing a major renovation, it’s a good time to have your venting system evaluated and discuss upgrade options with your contractor.
- Replacing existing white PVC venting is often a straightforward project, particularly when the vent pipe is easily accessible. Homeowners can contact All Comfort Services or another qualified HVAC contractor to determine whether an upgrade is appropriate for their home.
What Homeowners Should Know About UL 1738
Gas-burning appliances have traditionally been vented using white PVC pipe. While PVC is widely used in plumbing and performs exceptionally well for transporting water, it wasn’t originally developed or tested specifically as a venting material for combustion gases.
As heating equipment has become more efficient, venting requirements have evolved alongside it. Modern high-efficiency appliances produce cooler exhaust that often allows plastic venting materials to be used, but not every plastic pipe is manufactured or tested for the temperatures, pressure, and chemical conditions found in these systems.
That’s where UL 1738 comes in. UL 1738 is a safety standard for venting systems used with gas-burning appliances. Products certified to this standard have been evaluated for their ability to safely handle flue gases, condensate, temperature fluctuations, and long-term performance in venting applications.
For homeowners, the distinction may not be obvious because different types of plastic pipe can look nearly identical. That’s why it’s important to have gas-fired appliances installed and serviced by qualified professionals who understand current code requirements and specify venting materials that are listed for the intended application. Using a UL 1738-certified venting system helps ensure the materials are designed and tested specifically for safely venting combustion gases.
Recommendations for Homeowners
For now, UL 1738-certified venting systems are not required for most single-family homes and duplexes. However, many contractors recommend them because they’re specifically designed and tested to vent combustion gases and can help bring your home into compliance with emerging industry best practices.
If you’re planning to replace your furnace or water heater, ask your installer whether a UL 1738-certified venting system is the right choice for your home. Upgrading the venting system while the appliance is being replaced is often the most convenient and cost-effective time to do so.
Even if your existing appliances are still in good condition, replacing the venting system is often a relatively straightforward project, particularly when the vent pipes are exposed. If the piping is concealed behind drywall, additional work will be needed to access and replace it. For homeowners planning to finish a basement or undertake a remodeling project in the future, upgrading the venting system beforehand can help avoid having to open finished walls later.
Frequently Asked Questions About UL 1738
This content is intended for general educational purposes and should not replace recommendations from your HVAC contractor, appliance manufacturer, or local building officials.
