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Originally Posted by Furnaceguy85

liberty, thanks for the help. the pig tail makes sense and ive seen that on other models. switch did not reset on its own untill i got moisture out of hose.

no prob, the pressure hose from the collector box being on bottom instead of top can apparently cause the line to accumulate condensation, make sure to check that next time you go out. Funny thing is that the manual says to put it on the bottom port, the York service guy had to have classes for its dealers telling you what to disregard in the manual LOL

liberty, thanks for the help. the pig tail makes sense and ive seen that on other models. switch did not reset on its own untill i got moisture out of hose.

You are working on one of the first ones that came out (MP11A). These had alot of condensate/pressure switch problems. Are you sure it was actually stuck or did you just reset it? These older ones didn't come with the pigtail loop in the pressure hose that comes off of the inducer. They all come with this little loop in them now that diverts the condensation back to the inducer, otherwise it messes with the transducer and any little bit of condensation buildup will cause it to throw a pressure switch code. Check all the drains to make sure they have perfect fall, also make sure the pressure hose that connects to the collector box is on the top port. I would also tell your distributor to give you the little pigtail hose that goes from the inducer to the transducer

*EDIT: They have also changed the specs on the pressure switches in newer models...

Maybe I'm not sure where your seeing the condensate but there is always some moisture in the inducer housing. I suppose some could have found its way down that tube. Maybe you got enough in there it couldn't close, i dunno. I would just replace it though.

sorry i guess what im asking is is what would make the condensation get all the way to the pressure switch? the inducer is pulling a negetive pressure. are the pressure switches used on york poorly constructed or is there a issue i can be missing. i have run into a similar problem on other york 90% furnaces that are less than 5 years old. not modulators though.

So are you asking a question or just telling us how your call went?!

replace it.

stuck pressure switch on york furnace

was on a call today and ran across a stuck open pressure switch fault on a york furnace. 90% 80,000 btu upflow modulating natural gas furnace.

model# YP9C080B12MP11A
serial# WOE8871705

was able to unstick pressure switch and is working fine now. i found a couple of droplets of condensation at pressure switch port and in tubing. this is the pressure switch off of inducer motor and not the one tat goes to the secondary heat exchanger cover. even though everything is working now i have a feeling that the same problem will result.

thanks for your help.