Go Back  DoItYourself.com Community Forums > Heating, Cooling, Air Conditioning, Ventilation and T-Stat Controls > Thermostatic Controls
Reload this Page >

RTH9580WF boots up for heat only config but not when cooling is added

RTH9580WF boots up for heat only config but not when cooling is added


  #1  
Old 12-16-14, 03:56 PM
D
Member
Thread Starter
Join Date: Sep 2007
Posts: 22
Received 0 Votes on 0 Posts
RTH9580WF boots up for heat only config but not when cooling is added

I installed a RTH9580WF to control one of three (gas hot water boiler) heating zones in my home. The other two are controlled by HW programmables. All is fine with them. Wasn't able to get the 9580 to initialize at first. Blank screen. Got the 9580 to initialize only when the heat side was connected and A/C wasn't. For heat - Rh to R with jumper, W & C wired per spec. No other connects. 9580 is just fine on heat only. But with heat side connected and then adding the A/C side - Rc to Rc, G & Y as required, no jumper, the 9580 will not initialize/boot up. Blank screen. Voltage checks are OK except for one: Rh to Rc gives 12.5 V. Was expecting 48 V or 0. A/C has separate xfrmr and heating zone valves have their own. Voltages across all other pin combos are 24V or 0 where expected. I'm suspicious of how the 9580 reacts to the 12.5 V R to Rc, but other than that, not sure what to make of it. Ideas?
 
  #2  
Old 12-16-14, 04:50 PM
P
Temporarily Suspended
Join Date: Jul 2008
Location: NY
Posts: 10,982
Received 0 Votes on 0 Posts
Idea #1 Honeywell is drowning. Idea #2 Call their tech support anyway. 800 468 1502 Idea #3 You might disturb (wake up) their tech support in India but he or she will talk to you anyway.
 
  #3  
Old 12-16-14, 05:05 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 62,066
Received 1,505 Votes on 1,393 Posts
If you are going to use the T'stat for independent heating and cooling units ...... the cooling side supplies the 24vac to the t'stat.

Heat side...
R ---> R
W ---> W
No C connection to boiler.

Cool side....
R --- > Rc
C --- > C
G ---> G
Y ---> Y
 
  #4  
Old 12-16-14, 05:33 PM
D
Member
Thread Starter
Join Date: Sep 2007
Posts: 22
Received 0 Votes on 0 Posts
Dang - they don't tell you that in the manual. Thanks a bunch PJ! After the holidays I'll pull a new 18/5 run, (existing is heavier than 18 and is 3 wire non-std colors) and reconfig it. No hurry I guess; don't expect I'll need cooling anytime soon in northcentral PA.
 
 

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