[left]Hi, I have an old (early 90s) Rudd Silhouette gas furnace. My inducer was making a real bad noise so I bought a new one and replaced it today. It seemed to go smoothly but unfortunately I must have messed something up. It actually worked perfectly the first time after installing the inducer but at some point in the following 6 hours it stopped working. Now when I turn on the thermostat, the inducer turns on but then I never hear any "click" and the furnace never lights. I believe (based on reading a bunch of stuff on the internet) that this is the pressure switch not closing. Couple things I've done: * Made sure all the screws securing the inducer to the collector box are tight and the seal to the exhaust seems good to me. * Checked the tube to the pressure sensor, there are no cracks and it seems to have a good connection at both ends. At the same time I replaced the inducer, I also changed out the duct work going to my water heater (which connects to the furnace exhaust pipe). When I originally put in the water heater, I had a section of pipe sloping down. So while I had the inducer out, I rearranged things. The connections between sections of pipe and elbows and the vent hood are not as good as they were before (they were really clamped on there). Could this have an impact on the pressure sensor? I took a video to help explain, here it is: [url]https://www.youtube.com/watch?v=p1wv56ZVHKc[/url] I'm at my wits end trying to figure out what it might be, thanks for your help![/left]

I have a 10 year old Carrier 58CLR oil fired hot air furnace. Starting the end of last week it started behaving strangely. We'll have the thermostat call for heat and the furnace will start normally (Burner pre-purge, ignition, burn beyond flame sensor shutdown/lockout). Shortly after the burner starts the fan to circulate the air across the plenum/heat exchanger starts. I know that under normal operation when the thermostat stops calling for heat the burner will shut down, but the circulating blower will continue for a few minutes to cool the plenum/heat exchanger down. The weirdness is that now the blower stays running for much longer. I thought it was controlled by a timer, but now I'm wondering if there is a plenum temperature sensor that is going bad and reporting a higher plenum temperature causing the fan to stay on. I've also found that at this point if the thermostat calls for heat again while the air circulator is still running the burner doesn't turn on. I know the burner could be in lockout if the flame blew out, however when I hard reset the furnace (turning off the main power and back on) the burner ignites normally, I've also cleaned the flame sensor to make sure that it is working, and if I turn on the furnace without fuel turned on the system shuts down because there is no flame, so that appears to be working properly. My only hypothesis is if there IS a temperature sensor it is causing the system to think there is a hot plenum so keep the blower blowing and don't bother turning on the burner. Does anyone know if there is a temperature/limit sensor on the Carrier 58CLR low-boy furnace, and where it might be or how to access/test/change it? I haven't been able to find a service manual for it, and the installation manual I found doesn't specifically address this point. Or if I'm completely barking up the wrong tree I'm willing to be told so and any suggestions for where I should be looking would be gratefully accepted. Thanks, Metalmangler