Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 06-25-2009, 10:18 AM   #1
Member
 
fastback4's Avatar
 
Join Date: Apr 2008
Location: Kentucky
Posts: 33
Share |
Default

Voltage drop at thermostat


I get 28v at the furnace controller at the R and C (red & blue wire) posts. At the thermostat i get 8v at the R & C (red & blue) wires. White,Green & Yellow are 28v. Is this normal or is this bad....Regards......Tom

fastback4 is offline   Reply With Quote
Old 06-25-2009, 01:01 PM   #2
Member
 
Join Date: Dec 2008
Location: West Michigan
Posts: 440
Default

Voltage drop at thermostat


Is the common {C} terminal on the thermostat wired to the furnace. 28v between R and W,Y,and G is normal if the stat is not calling for heat or cool or fan.

SKIP4661 is offline   Reply With Quote
Old 06-25-2009, 01:48 PM   #3
Member
 
fastback4's Avatar
 
Join Date: Apr 2008
Location: Kentucky
Posts: 33
Default

Voltage drop at thermostat


The common C wire (blue) is wired to the furnace controller but not wired to the thermostat. I've been told this common blue wire will need to be used if i upgrade my thermostat to a programmable lcd readout type thermostat. Is this a fact?.........Tom
fastback4 is offline   Reply With Quote
Old 06-25-2009, 04:44 PM   #4
Member
 
Join Date: Jul 2008
Location: NW of D.C.
Posts: 5,990
Default

Voltage drop at thermostat


http://www.hvacmechanic.com/tstatwiring.htm

Post a schematic of 'stat to furnace wiring. We will find the missing 20vac.
Yoyizit is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Remote sensor for line voltage thermostat? hbridge HVAC 7 07-06-2012 03:42 PM
how to wire a low voltage thermostat to a baseboard heater db3iii HVAC 4 06-05-2009 08:03 PM
Low voltage thermostat wiring dirtpig538 General DIY Discussions 2 02-14-2009 12:48 PM
Voltage drop fix I discovered... rgsgww Electrical 12 12-09-2008 05:21 PM
Voltage Drop Issues sushiboy Electrical 12 04-03-2008 09:01 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.