Exhaust from Furnace
When exhaust gases discharged from a high-efficiency furnace exhaust vent meets the cold air, the air condenses faster than conventional furnaces because it is cooler. This condensing process, along with the one that occurs within the high-efficiency furnace itself, creates moisture that can collect and freeze around and inside exhaust pipes since it can’t travel far enough away from the home before condensing. As the furnace continues running through its heating cycles, to maintain the thermostat’s set temperature in the home or business, more condensing occurs, and ice continues to build-up.
When this build-up continues occurring, the furnace will automatically shut itself down as a safety precaution, during extremely cold winter weather. If the build-up is occurring on yours, turn off the power to the furnace, clear the pipes and then turn the power back on. If there is still an issue, call a heating contractor. You do not want this to happen because it can create a potential for freezing pipes. Be careful and continue to check them.