Furnace pressure switch issue
 

Hi,

First the details, just bought my first place a condo. My furnace is a Honeywell 58PAV045-17108 series 170.

I have been getting the diagnostic code 23: Pressure switch did not open - check for obstructed pressure tubing - Pressure switch stuck closed.

I had a professional come out Saturday night and he ended up saying my pressure switch was bad. So I ordered a new one and just installed it. I am getting the same 23 code!
I have blown through the tube and stuck a paper clip in there to clear out whatever no joy.
What’s weired is that if I turn it on for a call for heat I get the flashing code, but if I take the rubber tube out or pinch the rubber tube the furnace will light right up!
What is going on here?!??
Thanks!
:wallbash:

most likely its a obstructed port at the inducer, or a plugged plue pipe.Blowing into a pressure switch tube can ruin the pressure switch.Are you able to post a picture of your furnace with the top door off?

only 2 terminals on the pressure switch pressure? switch should close after the induced draft motor starts to OK the spark and inturn opens the main burner

I don't think a 58 pav had spark ignition. it should have an ignitor...........but your spot on about the operation of the switch......we know the inducer is running....he said the furnace lights if he pinches the tube leading from it.

wow all these replies already! Thanks!

Yes the pressure switch has two terminals.
Yes the inducer does run as the furnace works when I pinch it then the next time it calls for heat it gives the flashing code.
Yes it's an ignition.

Don't think the flu is plugged as this is a condo building so other floors would have a problem if that was the case (I think).

Here are pictures, https://picasaweb.google.com/1119066...eat=directlink

Where is the inducer? Is that something I could get to and check?

I took off the piping leading to the ceiling and turned on the system for a few seconds as that is what the guy told me to do to get anything stuck in there out. I didn't see anything.

Here are the manuals,
link
2nd link

OK here is what i want you to try next,1 st kill the power to the furnace.then take the rubber hose off of the connection at the furnace, leave it on the switch. Then using a paper clip that has been straighten out......poke into the fitting toward the furnace. Some times condensation causes build up in that port........the paper clip should go in pretty deep, at least 1/2 way or more.......let me know what happens.

the inducer draft motor is above the gas valve there....you only have ONE tube connection on it from the ID fan housing.that switch has to be open before a cycle starts if the control board sees a closure prior to the ID starting the system will not start..the ID fan ait closes the pressure switch...to start ignition

thanks harley, I have done that with a paper clip and also with a long tube that fits on canned air that fit perfectly. Both went in easily and nothing was on them. I even sprayed the canned air in there.

If you take the flue pipe off of the furnace does the furnace start up and run with out pinching the rubber tube? ( DO NOT LEAVE IT OFF, DO THIS STRICTLY FOR DIAGNOSTICS )

I'll try it and get back to you.

No it does not.

If i was there I could use my magnihilic and test the drat, but i am not. I suspect that there is a problem with the draft inducer or the collector box area. I am afarid that you are going to need to have a company come out and look at it. They will need to be able to measure draft.

Ok I was just talking to a repair guy and I told him how the little fan on the inducer motor was really spinning fast. He told me to hold it to stop it from spinning and the furnace kicked right on!!

That little fan is always running. Should that be the case? It turns really fast also.

He was saying there may be too much draft also. Weird as I'm on the 3rd floor of a 6 story building I would think the other 5 people using the same tubing would have the same problem... He was saying I may need a damper of sorts on the roof and that the building may be using some kind of power "thing" to get the gases out also (don't quote me on the last part :) ).

Again thanks for the help

OHHHHHHHHHHHHHH:huh: now i see what you dealing with if the building is using a booster exhaust hood for the flue riser that drafting thru the units in the builing are sucking air..causing the motors to spin and causing the PSI control to close before the stat calls to actually run the ID...check with your neighbors.if it is just a common draft riser with no fan booster pulling thru the condo furnaces somebody needs to be experiencing your situation also...if they have units the same with the Induced draft motor design...they might just have staic flue piping going into that riser....

As Ace has already posted a manometer reading of the vacuum at the preasure switch should be taken.

Average readings for the 58PAV run between -.66"wc and -.33"wc. with the inducer running.
A vacuum should not be present when the inducer is not running.