If a condensate drain becomes clogged in a high-efficiency boiler, what is the most likely risk?

• A. Condensate buildup can cause overflow or freezing, leading to shutdown or water damage.
• B. It increases combustion efficiency
• C. It improves venting
• D. It has no effect

Answer: (A)

When a high-efficiency boiler loses a clear way to drain its condensate, the liquid has nowhere to go and will back up. That backup can overflow the drain or freeze in cold weather, potentially triggering a safety shutdown and causing water damage around the unit. This risk is about drainage failure leading to shutdown and damage, not about changes in efficiency or venting.