Honeywell TH9421C1004 Issues


  #1  
Old 04-29-16, 06:08 AM
K
Member
Thread Starter
Join Date: Apr 2016
Location: USA
Posts: 8
Received 0 Votes on 0 Posts
Honeywell TH9421C1004 Issues

Hey everyone,

Our tstat will not change modes (heat/cool) - like the touchscreen is not working - kind of - if I touch the "System" area to change from heat to cool - the backlight comes on, so it's seeing the touch, but it will not change from heat to cool.

Other areas on the screen exhibit the same issue - can tap the "clock" button - backlight comes on, but no clock settings function - same with the "Screen" button, and Fan area

About the only area that works is the Up/Down setting buttons and the "More" button

this thing is 8 years old - does not show a "Screen Locked" message

anyone have any ideas on what i can try?

Thanks,
Mike
 
  #2  
Old 04-29-16, 10:00 AM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,425
Received 17 Votes on 14 Posts
https://customer.honeywell.com/resou...69-1815EFS.pdf

I would verify that Function 670 is 0 (unlocked) on that Honeywell VisionPro IAQ.

I don't remember if you get a Locked message when 670 is 1 (partially locked)
 
  #3  
Old 04-30-16, 04:46 AM
K
Member
Thread Starter
Join Date: Apr 2016
Location: USA
Posts: 8
Received 0 Votes on 0 Posts
Thanks for the reply. I wondered that myself, but not sure how I'm going to find out. The screen does not respond when I tap the "System" button, so I can't get to the screen with the 5 empty boxes to access those system settings.

I kind of think this thing is toast - now trying to determine if there is a compatible replacement stat.
 
  #4  
Old 04-30-16, 06:18 AM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,425
Received 17 Votes on 14 Posts
It sounds like it is toast.

The Honeywell Prestige IAQ would be (and currently is) my choice.

It will do everything that your existing thermostat can do plus more.

The Prestige IAQ requires 2 wires between the EIM and the stat and the existing VisionPro IAQ required 3 conductors.
 
  #5  
Old 04-30-16, 07:19 AM
K
Member
Thread Starter
Join Date: Apr 2016
Location: USA
Posts: 8
Received 0 Votes on 0 Posts
thanks for the reply. Does the Prestige require a diff EIM?
 
  #6  
Old 04-30-16, 09:27 AM
K
Member
Thread Starter
Join Date: Apr 2016
Location: USA
Posts: 8
Received 0 Votes on 0 Posts
looks like it does - looks like this is what I need

http://www.amazon.com/Honeywell-YTHX...qid=1462032866

do I have to hook up those extra sensors for this to work?
 
  #7  
Old 04-30-16, 12:01 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,425
Received 17 Votes on 14 Posts
You do not have to connect the duct sensors but it is a great option.

I connect the sensors then run heating or cooling and set the stat to notify me if the delta tee is too far under or above my readings.
 
  #8  
Old 05-01-16, 04:06 AM
K
Member
Thread Starter
Join Date: Apr 2016
Location: USA
Posts: 8
Received 0 Votes on 0 Posts
thanks!

I'm seeing part numbers like YTHX9421R5127WW, or YTHX9421R5101WW/U and the aforementioned one - YTHX9421R5085WW

are these different revisions? is the 5127 the latest rev?
 
  #9  
Old 05-01-16, 05:51 AM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,425
Received 17 Votes on 14 Posts
The 5085 has the stat, EIM and 2 duct sensors.

The 5101 has the stat, EIM, 2 duct sensors and a wireless outdoor sensor.

The 5127 has an Internet gateway, 2 sensors, stat and EIM but no outdoor sensor. It would be my choice. The wireless outdoor sensor isn't great.

All 3 options have the new stat with a thin border, and the new EIM with 4 sensor inputs plus the 3 sets of dry contacts. The older EIM only supports 2 sets of sensor inputs plus the dry contacts.
 

Last edited by Houston204; 05-01-16 at 06:09 AM.
  #10  
Old 05-03-16, 06:17 AM
K
Member
Thread Starter
Join Date: Apr 2016
Location: USA
Posts: 8
Received 0 Votes on 0 Posts
ok, I have the 5085 kit in hand - about to start the swap out - wish me luck!

anything particular / hints / etc - I need to be aware of for this?
 
  #11  
Old 05-03-16, 09:26 AM
K
Member
Thread Starter
Join Date: Apr 2016
Location: USA
Posts: 8
Received 0 Votes on 0 Posts
I have a water sensor in the bottom of the pan under this unit - it is spliced into the wire that connects the "Y" terminal on the old VisionPro EIM to the outside unit.

I will only have one S terminal available if I use the supply/discharge sensors (I plan to - maybe not today though) because I also have the wired outdoor temp sensor.

do you think I should leave the pan sensor connected as it is, or move it to the one free S terminal.

everything else moved easily and seems to be working fine.

thanks in advance!
 

Last edited by kernel27; 05-03-16 at 11:11 AM. Reason: corrected the terminal the water sensor is spliced into
  #12  
Old 05-03-16, 06:54 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,425
Received 17 Votes on 14 Posts
Either way will do the job.

If you wire the float switch into your EIM you must configure for System Shutdown Alert. If you configure for Full Drain Pan Alert it will not turn off the condenser when the float switch trips.
 
  #13  
Old 05-04-16, 06:49 AM
K
Member
Thread Starter
Join Date: Apr 2016
Location: USA
Posts: 8
Received 0 Votes on 0 Posts
thanks! just to clarify - the way it currently is - in the "Y" loop - if that float sensor trips - the new t-stat will tell me on the screen that there is an issue?
 
  #14  
Old 05-04-16, 10:05 AM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,425
Received 17 Votes on 14 Posts
If you install the duct sensors and set it to alert you if the cooling Delta t is less than 16°F, you will get a Delta t alert when the float switch trips. The float switch would be one of many possible causes.

If you wire the float switch to the EIM and get a system shutdown alert you will know it is the float switch.
 
 

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