The winter is approaching, I noticed that the furnace in the attic might have problem, here's the symptom: The fan was running while the thermostat was set "heat on" with room temperature lower than the temperature set, the vents kept blowing cool air. Hence the fan didn't stop by itself, so I had to turn the thermostat from heat to off manually to avoid having the fan to run for long time, while no fire was in the furnace I assume. Later I turned the heat back on and things looked normal and the rooms were warmed up. The issue happened several times per week, but I could hardly reproduce the issue when I tried to troubleshoot. I went up to the attic and I saw no error light on the system board(which normally gives an error code), and when I was at the attic to test and monitor, it always worked. I replaced the frame sensor rod with a new one last week, but the issue has happened another 3 times since then. Any idea or suggestion? Also, when I was in the attic and had the top cover removed, I noticed a brownish liquid running(really quickly, just about one second and no more, and I only saw that once, although I believe it could happen often hence we can see the brownish leaking line), please see the attached pictures below, does it indicate another problem? Thank you so much! [img]https://cimg1.ibsrv.net/gimg/www.doityourselft.com-vbulletin/1500x2000/furnace1_a39231abf35f6625263a3ce0508a9366f093d53f.jpg[/img] [img]https://cimg7.ibsrv.net/gimg/www.doityourselft.com-vbulletin/708x839/furnace2_d50bdc3931885a7a47e7c23077e9e281fd5d546e.jpg[/img] [img]https://cimg5.ibsrv.net/gimg/www.doityourselft.com-vbulletin/1500x2000/furnace3_d6998e41611c1d802d9edfe988696e86a6153967.jpg[/img]

[color=#141414]House built 3 and 1/2 years ago with XR95 furnace installed when built. Won’t put out any heat today. Light shows 3 flashes the pauses. Manual says this is a pressure switch error. Any tips on what I can check at home before calling for service on Monday?[/color]