According to UL standards, what is the minimum temperature at which medium heat appliance flue gases must comply with UL 959?

The correct choice for the minimum temperature at which medium heat appliance flue gases must comply with UL 959 is 1000 degrees. This standard is significant as it deals with maintaining safety and performance specifications for medium heat appliances, particularly concerning the flue gases they produce.

At this temperature, the flue gases can be appropriately vented without compromising the appliance’s efficiency or safety. This high threshold is established to ensure the materials and structures involved can withstand excessive heat, preventing potential hazards like damage or failures in the venting system.

Understanding the UL 959 standards is crucial for ensuring that installations meet the necessary regulatory requirements for safe operation of heating appliances. Adhering to these temperature guidelines ensures effective combustion and minimizes the risk of flue gas-related incidents.