Boiler frequently locks out during very cold weather but runs fine in mild temperatures

Safety: Use caution on icy surfaces when inspecting outdoor terminations.

• Step 1 – Clear snow and ice: Inspect the Triangle Tube boiler’s intake and exhaust terminations. Remove snow, ice, or frost buildup.
• Step 2 – Protect condensate line: Ensure the condensate drain is insulated or heat-traced if it runs through unheated spaces. Thaw any frozen sections and correct slope.
• Step 3 – Outdoor sensor check: Verify the outdoor sensor is not directly exposed to wind or sun that could cause erratic readings.
• Step 4 – Gas supply: If other gas appliances also struggle in cold weather, contact your gas utility to check supply pressure.
• Professional evaluation: A technician should verify combustion settings and venting design for cold climate operation.