We have been getting an error on occasion for 271 low pressure switch open on our icomfort thermostat. I purchased a new pressure switch and when I installed it the furnace would not close the switch. I put the original on and it works. Both are the same rating of .5 /.9 pf (two stage). I'm getting 27v at the switch. I read the pressure with a manometer and it is reading 2.12 inches of wc. I tried it a few times and get the same reading. Since it is so much higher than the pressure switch rating , could it causing it not to close? I actually purchased another pressure switch thinking the first was a dud and neither of the replacements will work, but the original does just with intermittent issues. The flue and intake are clear and I blew out and inspected the hoses and they look fine and clear. Any ideas why neither of the new switches will work? Thank you in advance.

Hi all, trying to accomplish a few things but need some help identifying the "vent thing" in the middle between the furnace and the hot water heater: [img]https://cimg3.ibsrv.net/gimg/www.doityourselft.com-vbulletin/1384x1992/img_6916_d72bcd37bf05b0d482d59fbf7d215321e3091833.jpg[/img] We have a heat pump - is this for the heat pump? Thinking of replacing the heat pump for a traditional furnace/AC combo. If that middle thing is for the heat pump, does it go away if we replace the heat pump?