What practice is essential to prevent backdrafting in gas appliances?

Preventing backdrafting in gas appliances is crucial for ensuring safe and efficient operation. Proper flue and venting configurations are essential because they facilitate the correct exhaust of combustion gases. When a gas appliance operates, it produces combustion byproducts, which must be vented outside to prevent harmful gases, such as carbon monoxide, from entering living spaces.

A correctly designed and installed flue system creates the necessary draft to direct these gases outside, while also ensuring that sufficient air is available for combustion. If the venting system is blocked, improperly sized, or inadequately configured, it can lead to backdrafting, where the combustion gases flow back into the building instead of venting outside, creating potential safety hazards.

In contrast, the other options do not effectively address the risk of backdrafting. Using lower grades of gas does not mitigate the problem of gas buildup; installing additional gas appliances could exacerbate venting issues, and reducing air intake can increase the likelihood of inadequate combustion air supply, contributing to backdrafting rather than preventing it. Therefore, ensuring proper flue and venting configurations is the most effective practice to prevent backdrafting in gas appliances.