Abstract: A freeze resistant method for draining liquid condensate from a condensate furnace includes quickly purging the liquid condensate from a condensate reservoir. A condensing heat exchanger connected to a condensing reservoir stores liquid condensate as the system is in use. An inducer produces a positive pressure along a condensate line to the outlet of the reservoir, creating a back pressure which prevents draining of the reservoir. When the inducer is shut off, the positive pressure is removed, and the liquid condensate rapidly flushes from the reservoir. The amount of liquid condensate remaining in the system and exposed to cold conditions can be minimized.

Abstract: A freeze resistant method for draining liquid condensate from a condensate furnace in low temperatures includes quickly purging the liquid condensate from a condensate reservoir. A condensing heat exchanger is connected to a condensing reservoir and stores liquid condensate as the system is in use. As the inducer is running, it produces a positive pressure along a condensate line to the outlet of the reservoir, creating a back pressure which prevents draining of the reservoir. When the inducer is shut off, the positive pressure is removed, allowing the outlet to open, the liquid condensate rapidly flushing from the reservoir. By flushing the liquid condensate out of the system rapidly, the amount of liquid condensate remaining in the system and exposed to cold conditions can be minimized. Alternatively, a valve can be positioned proximate to the output of the condensate reservoir and is opened when the liquid condensate is to be flushed from the system.