Thermostat for PTAC? Applied Comfort scwc15k00q7a42

Reply

  #1  
Old 05-15-20, 12:57 PM
W
Member
Thread Starter
Join Date: May 2020
Posts: 2
Received 0 Votes on 0 Posts
Thermostat for PTAC? Applied Comfort scwc15k00q7a42

I have an Applied Comfort scwc15k00q7a42 PTAC in my apartment. The unit has 1/2 (low/high) heating and 1/2 cooling settings, where the PTAC itself supplies AC, and in the cold parts of the year, heat is driven by blowing air thru a hot water radiator that is regulated by a zone valve connected to the PTAC.

My primary issue today is that the PTAC's built in thermostat isn't working properly -- it works, but doesn't cool lower than ~mid-70s. Almost seems like a calibration issue, as if I hold the "sensor," it starts cooling again from the warmth of my hand. Any general suggestions around what could be causing that?

Separately, if I'm going to try to fix this, it occurred to me that it might be nice to try to wire in a smart thermostat ala Ecobee or Nest. Is this even an option? Wiring diagram and what I can see in the AC are 3 wires coming in/out of the thermostat... red, white, black.

Here's the link to the AC & parts list: SCWC15K00Q7A42 Service Parts | Applied Comfort Products
Here's their PDF of the wiring diagram: http://www.ptacs.com/static/products/wiring/802599.pdf

Any help or advice would be appreciated. Let me know if I missed any crucial info. Thank you!
 
Sponsored Links
  #2  
Old 05-15-20, 09:42 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 56,343
Received 741 Votes on 696 Posts
Welcome to the forums.

In order to use a wifi stat.... you would replace that current thermostat with a high current relay that could be controlled by a low voltage thermostat. It could control temperature but not turn the unit on or off or change blower speed. That would require extensive work and not be easily done via online help.

That thermostat is a basic remote sense bulb type. There may be a screw somewhere on it to recalibrate it. They aren't really designed to be recalibrated. If you find the screw..... you must turn it a little at a time and keep track of exactly which way and how much you changed it.

Name:  stat.jpg
Views: 24
Size:  19.1 KB

 
  #3  
Old 05-18-20, 07:20 AM
W
Member
Thread Starter
Join Date: May 2020
Posts: 2
Received 0 Votes on 0 Posts
Thanks PJmax. Sounds like a definite "no" on the smart thermostat.

I didn't notice any screws on the existing, but will take a look the next opportunity I have. Also trying to locate a replacement to potentially just swap in a new part.
 
  #4  
Old 05-18-20, 10:07 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 56,343
Received 741 Votes on 696 Posts
That is an 800617 thermostat.
Not too many choices in locating it.
It's possible with the temperature spread known to locate a universal one.
There may be an original mfg part number on the old one.


Williams HVAC
Applied Comfort
 
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
 
Ask a Question
Question Title:
Description:
Your question will be posted in: