York Diamond 90 - 3 Code

Reply

  #1  
Old 12-14-14, 08:55 AM
Member
Thread Starter
Join Date: Dec 2014
Location: US
Posts: 2
Received 0 Votes on 0 Posts
Question York Diamond 90 - 3 Code

I purchased a home which has a York Diamond 90 converted to propane/high-altitude. In calling for heat, I get the 3-flash code which indicates the pressure switches are not closing for one reason or the other. I have eliminated everything on the list that is associated with this error code. I have taken both pressure switches out of the equation by bypassing each one separately, and also both at the same time. I did this using a jumper wire. I'm a qualified electrician, and have been involved with commercial/industrial electrical systems for over 35 years. This problem has me stumped.

The inducer motor comes on, but nothing else happens. The igniter and gas valve are not seeing any power. This furnace looks like new - there is no discoloration at all around the flame sensor, or anywhere in the burner box for that matter. It's like it was never fired.

Does anyone have any ideas as to what could be going on? I appreciate your time. I know this has been asked and answered before, but in reading every thread I can find about it, I'm still not getting anything to happen in this furnace.

Thank you
Dave S.
Cedar City, UT
 
Sponsored Links
  #2  
Old 12-14-14, 09:06 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 52,699
Received 344 Votes on 322 Posts
Welcome to the forums.


The inducer motor comes on, but nothing else happens. The igniter and gas valve are not seeing any power.
Until the pressure switch circuit is normal.... the igniter wont work and the gas valve wont open. If you read the threads here almost every one has the same pressure switch issue.

You can't just bypass the pressure switches. They need to change status at a certain time to be considered working properly.

You need to remove the rubber lines connecting the pressure switch and make sure they are clean and not clogged. You need to check the little port on the inducer where the hose connects. Use a paper clip or other similar object to open the little hole.

Post the model number of your furnace. It can be found near the burner area.
 
  #3  
Old 12-14-14, 09:34 AM
Member
Thread Starter
Join Date: Dec 2014
Location: US
Posts: 2
Received 0 Votes on 0 Posts
The model number is (Z)P3DHD20N11201D

Ive followed the other threads and see that it's usually the pressure switches. I can apply a little pressure by blowing into the lines attached to the switches and can hear/feel them both closing and opening. I have cleared all the points where the different hoses attach to the switches and to the other parts. The paper clip only goes in about an inch or so before it hits something inside where they attach. I detached the hoses from the switches, and turned it on. When the inductor motor comes on, I don't feel any pressure at the hoses. Should I?
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
 
Ask a Question
Question Title:
Description:
Your question will be posted in: