Problem: I own several rental properties. I am having a problem with moisture buildup in my pressure tubes on my 80% furnaces. The tubes stop up with water and the furnaces shut down.
Answer: One or our customer wrote to us and said the following: “FYI, regarding moisture buildup in pressure tubes, I simply moved the pressure switch above where the tube connects to the inducer and the moisture problem went away (on both Goodman & Rheem furnaces)”. I have also found this water drainage problem to occur on furnaces because the furnace’s condensate drain line is stopped up. The furnace can not drain properly so the water backs up in the draft inducer and pressure switch then there is a “pressure switch failed to close” error on the furnace’s control board flash code. My remedy for solving this problem is to unstop the furnace’s condensate drain by first disconnecting the pressure switch sensing tube. It is very important to disconnect the pressure switch tubing from the inducer and other connections because using a wet vac or compressed air with the pressure switch tubing attached can damage the pressure switch. I would then either use a wet vac to suck the debris out of the condensate drain line or use compressed air to clear the stoppage so the condensate drain on the furnace can drain properly. Below we have a really good Youtube video which shows how to troubleshoot pressure switch problems. This Youtube video was made by grayfurnaceman. Thanks, grayfurnaceman! We sell many different types of pressure switches on the following page: Please click here to see the pressure switches we sell. If you have any other questions please email us firstname.lastname@example.org or comment below. We would love to help you out and have your business!