ICC Commercial Mechanical Practice Exam

If a chimney has an installed flue lining system, can other appliances vent through that system?

1. Yes, as long as the appliances are compatible

2. No, it is prohibited

3. Yes, if properly modified

4. None of these

The correct answer is: No, it is prohibited

When a chimney has an installed flue lining system, it is crucial to understand the regulations regarding venting multiple appliances through that system. It is generally prohibited for multiple appliances to vent into a single flue lining unless specifically designed to do so and permitted by relevant codes. This prohibition helps to ensure safety and efficiency in venting systems. Compatible appliances might include those that operate on similar principles, such as having the same type of venting requirements or operating temperatures. However, even if appliances are compatible, each appliance often has its specific venting needs and requirements dictated by local codes or manufacturer specifications. Additionally, modifying the system to accommodate multiple appliances can lead to unintended consequences, including issues with backdrafting or poor performance. Each appliance can create pressure differentials that might disrupt proper venting if they share a flue lining. Hence, the correct answer aligns with safety practices and building codes that prioritize individual venting for appliances to mitigate these risks.