# Condensate not draining while the induced draft blower is running



## conservationcontrols (11 mo ago)

I have a Rheem hi-efficiency furnace. While the furnace is on and the induced draft blower is running, the condensate doesn't drain out of the heat exchanger and the condensate pressure switch trips after is has been running for a while. I disconnected the condensate drain line while the furnace was on, and the water would not come out of the drain hole. As soon as the draft inducer turned off, the water flooded out. It seems to be venting exhaust air just fine. It's almost like there is a negative pressure inside the heat exchanger that prevents the water from draining out. I don't believe the heat exchanger is plugged because it drains just fine as soon as the draft inducer turns off. Thanks!


----------



## bobber (Jun 24, 2021)

There IS negative pressure inside the heat exchanger. You might need a trap where the water flows out to seal out the negative pressure so it will drain. Also you need an open air fitting at the drain, so there's no seal there.


----------

