Blogs & Bulletins
When designing a high-efficiency gas boiler or commercial boiler heating system, every component matters. For equipment manufacturers, selecting the right common venting components is more than performance. It is also about certification, product development costs, installation requirements, and ensuring the finished appliance meets applicable standards.
Centrotherm’s standard Non-Return Valves (NRVs) are now certified to CSA/ANSI Z21.66:23 • CSA 6.14.23, Automatic Damper Device for Use with Gas-Fired Appliances. This certification provides equipment manufacturers with a ready-to-integrate solution for common vent applications, helping simplify product development and reduce the need for additional certification testing.
For manufacturers of commercial boilers and high-efficiency gas appliances, this is an important step toward a more streamlined, compliant, and cost-effective venting solution.
What Is a Non-Return Valve in a Common Vent System?
A Non-Return Valve, or NRV, is a backflow prevention device used in common vent installations. It helps prevent the reverse flow of flue gases into idle appliances connected to a shared venting system.
In a commercial common vent application, multiple gas-fired appliances may share a single venting system to safely direct flue gases outdoors. When one appliance is operating and another is idle, the system must be designed to manage flue gas flow appropriately. An NRV helps prevent flue gases from flowing back into an idle appliance, supporting the safe and intended operation of the common vent system.
For equipment manufacturers, integrating an NRV into a gas-fired appliance can be an important part of developing a complete common venting solution. The component must be suitable for the appliance design and meet the applicable certification requirements.
Why CSA/ANSI Z21.66 Certification Matters to Equipment Manufacturers
CSA/ANSI Z21.66:23 • CSA 6.14.23 is the applicable standard for automatic damper devices for use with gas-fired appliances. Certification to this standard demonstrates that a qualifying device has been evaluated against the requirements of the standard.
As CSA requires automatic damper devices to meet this standard, selecting a certified NRV is an important consideration for equipment manufacturers developing appliances for common vent installations.
Centrotherm’s standard NRVs are certified to CSA/ANSI Z21.66, giving manufacturers a component that can be integrated into their appliance design without the need to independently certify the NRV itself under the same standard.
This saves equipment manufacturers time and money by allowing them to use a CSA-certified NRV without having to certify the same component again.
Reduce Certification Testing Costs
For equipment manufacturers, product certification is a necessary part of bringing a commercial boiler or gas-fired hot water boiler to market. However, additional testing of individual components can increase development costs and extend the timeline for product approval.
Historically, an equipment manufacturer may have needed to arrange and pay for certification of an NRV as part of its common venting system.
With Centrotherm’s standard NRVs already certified to CSA/ANSI Z21.66, equipment manufacturers can integrate a certified device into their appliance design without incurring the cost of independently certifying that NRV to the same standard.
This can help reduce:
- Independent component certification costs.
- Engineering resources required to coordinate additional testing.
- The cost of developing a common venting solution.
By choosing a certified component from the outset, equipment manufacturers can make more efficient use of their product development budgets while maintaining focus on appliance performance and design.
Shorten Product Development Lead Times
The development of a commercial boiler or high-efficiency gas boiler requires careful coordination between engineering, testing, certification, and manufacturing teams. When a component requires separate certification, it can introduce additional scheduling and testing requirements.
Centrotherm’s CSA-certified NRVs offer equipment manufacturers a more streamlined path to integrating automatic damper devices into their appliances. Because the NRV is already certified to CSA/ANSI Z21.66, equipment manufacturers can avoid duplicating the certification process for the component itself.
This helps simplify the development process and may reduce the time associated with independent component testing. equipment manufacturers can spend less time managing additional certification work and more time progressing their appliance toward production.
The result is a more efficient product development workflow, with a certified common venting component ready to be considered part of the appliance design.
Support Compliance and Inspection Confidence
For manufacturers, compliance is an important consideration long after an appliance leaves the factory. Commercial boiler installations are subject to applicable codes, standards, and inspection requirements, and the use of appropriately certified components helps support a compliant installation.
Centrotherm’s CSA-certified NRVs provide equipment manufacturers with confidence that the device meets the requirements of CSA/ANSI Z21.66 for automatic damper devices for use with gas-fired appliances.
This can help reduce the risk of certification-related concerns during the appliance approval process or installation inspections. It also gives equipment manufacturers greater peace of mind that their selected NRV is supported by the appropriate certification.
A certified component can help avoid unnecessary questions or delays associated with an NRV that does not meet the applicable standard. However, certification of the NRV does not by itself certify the complete appliance or common venting system. The finished system must still meet all applicable requirements.
Demonstrate a Commitment to Quality
When selecting components for a commercial boiler heating system, equipment manufacturers need products that meet the required technical and certification standards.
CSA certification provides an independent assessment against the applicable standard. For Centrotherm’s standard NRVs, certification to CSA/ANSI Z21.66 demonstrates that the device has been evaluated to the requirements for automatic damper devices used with gas-fired appliances.
This provides a meaningful point of differentiation when comparing venting components. Equipment manufacturers can select a certified NRV rather than relying solely on unverified component claims or lower-cost alternatives that may not have been evaluated to the same standard.
For a manufacturer, this supports a more consistent approach to product quality, reliability, and certification throughout the appliance development process.
Simplify Common Vent Integration with Centrotherm
The right venting partner can make a significant difference to appliance development. Equipment manufacturers need suppliers that understand the demands of commercial gas-fired appliances and can provide components that are suitable for integration into their designs.
Centrotherm’s CSA-certified NRVs support a more streamlined approach to common venting by offering a certified automatic damper device that equipment manufacturers can integrate directly into their appliance.
This is particularly valuable for manufacturers developing:
- Commercial boilers.
- High-efficiency gas boilers.
- Gas-fired hot water boilers.
- Common vent systems for multiple appliances.
- Commercial boiler heating systems.
By choosing a certified NRV from Centrotherm, equipment manufacturers can simplify component selection and reduce the need for additional certification work. This helps make Centrotherm a strong partner for manufacturers looking to develop efficient, compliant, and cost-effective gas flue venting solutions.
Last Updated: 09/16/2026