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 05-02-2012, 11:27 AM   #1
Newbie
 
Join Date: May 2012
Posts: 5
Rewards Points: 10
Default

thermostat wiring


We bought an old house and *tried* to replace the thermostat. We followed the directions, but when it didn't work, we called a professional. Over 2 hours later, we believed that he had fixed the problem. Now, when are using our AC for the first time, we realized that he didn't fix the problem and we don't want to spend another few hundred dollars for this issue to maybe be resolved.

Here's what I've got:
A gas furnace in the basement
An AC unit on the roof
And a fan/blower

We purchased a simple Honeywell thermostat and we have cables connected to Y, G, W, and R ports. Everything is working fine with the heat. The AC works fine when you turn it on to cool manually. When the thermostat is set to automatic, the AC comes on the roof but the fan does not also come on. Thus, we have to manually turn the AC on and off.

From research online, it looks like this setup should work for older homes but we do not have the RC and RH ports. Should we purchase a new thermostat with the RC and RH ports and run a jumper cable between them? Again, fan, AC, and heat work, and fan works automatically with heat, but fan does not come on with AC when thermostat is set to automatic. Thanks.


Last edited by rejames; 05-02-2012 at 11:40 AM.
rejames is offline   Reply With Quote
Old 05-02-2012, 01:38 PM   #2
Member
 
Join Date: Oct 2010
Location: GA
Posts: 163
Rewards Points: 150
Default

thermostat wiring


What model thermostat do you have and what are the make/model of your gas furnance / AC. You may need to program the thermostat but it also maybe wired incorrectly.


Last edited by kilosos2; 05-02-2012 at 01:42 PM.
kilosos2 is offline   Reply With Quote
Old 05-02-2012, 03:55 PM   #3
Newbie
 
Join Date: May 2012
Posts: 5
Rewards Points: 10
Default

thermostat wiring


What model thermostat do you have and what are the make/model of your gas furnance / AC. You may need to program the thermostat but it also maybe wired incorrectly.

Thermostat: Honeywell RTH221
Gas valve for the furnace: Carrier 646A-X
I can't find the model number for the gas furnace but it's more than 20 years old.
AC: No idea it's on my roof
rejames is offline   Reply With Quote
Old 05-02-2012, 04:42 PM   #4
I'm Your Huckleberry
 
Join Date: Mar 2011
Posts: 5,876
Rewards Points: 2,204
Default

thermostat wiring


You shouldn't need a new thermostat as for the wiring bit but you may need a new furnace control board or a new stat if by some chance this one is defective and they sometimes simply are. I had one yesterday I had to return, right from the package it didn't work at all, and get another one that did. Second time I put batteries into the stat before I left Home Depot to make sure it lit up normally. Digital stat.

Here's what you do; turn the power to the furnace off by way of breaker. Remove stat cover to expose the terminals, where the wires are connected to

R-24 volts-power
Y-cool
W-heat
G-fan.


You'll need a small wire or some small gator clips to jump the Y terminal to the R terminal. This should give you the call for cooling. Turn the breaker to the furnace back on. If everything comes on than you need to replace the stat.

If not, do the exact same thing in the furnace on the control board, assuming you have a control board. I'll stop here until I know if your furnace does indeed have a control board or not.
__________________
Thanks.
Doc Holliday is offline   Reply With Quote
Old 05-02-2012, 04:49 PM   #5
Newbie
 
Join Date: May 2012
Posts: 5
Rewards Points: 10
Default

thermostat wiring


Just looked. I don't think that I have a furnace control board. All wires are going into a small white device, but it's not a board and it has no markings on it.

All systems were working fine with the former Honeywell thermostat that was not unreasonably old. It's just that there's a disconnect between the wiring in the furnace and the new thermostat. That being said, the technician could have altered the wiring in the furnace.

Last edited by rejames; 05-02-2012 at 04:54 PM.
rejames is offline   Reply With Quote
Old 05-02-2012, 04:57 PM   #6
I'm Your Huckleberry
 
Join Date: Mar 2011
Posts: 5,876
Rewards Points: 2,204
Default

thermostat wiring


What you got, an old Consolidated furnace? Either way, you have the control strip, transformer and fan relay. Uhg.

You can still do the bypassing of the stat but most likely to no avail. You may be right, he may have simply re-wired the furnace.

You just paid good money to an a/c company and the problem is not fixed. Call them back and ask for them to have their lead technician come out and fix this problem. You should not have to pay again.
__________________
Thanks.
Doc Holliday is offline   Reply With Quote
Old 05-02-2012, 05:05 PM   #7
AKA HVACTECHFW
 
Join Date: Nov 2010
Location: NE Indiana
Posts: 2,328
Rewards Points: 1,022
Blog Entries: 1
Default

thermostat wiring


What happens when you set the Fan to ON @ the stat? Does the blower turn on?
__________________
IT IS WHAT IT IS
hvactech126 is offline   Reply With Quote
Old 05-02-2012, 05:08 PM   #8
Newbie
 
Join Date: May 2012
Posts: 5
Rewards Points: 10
Default

thermostat wiring


What happens when you set the Fan to ON @ the stat? Does the blower turn on?

Fan turns on. Fan works in isolation. Fan works with heat manually and automatically. Fan works with cool manually. Fan does not come on when thermostat is set to automatic cool. AC comes on but blower does not.
rejames is offline   Reply With Quote
Old 05-02-2012, 05:14 PM   #9
AKA HVACTECHFW
 
Join Date: Nov 2010
Location: NE Indiana
Posts: 2,328
Rewards Points: 1,022
Blog Entries: 1
Default

thermostat wiring


Sounds like a bad stat if that is the case.
__________________
IT IS WHAT IT IS
hvactech126 is offline   Reply With Quote
Old 05-02-2012, 05:19 PM   #10
Newbie
 
Join Date: May 2012
Posts: 5
Rewards Points: 10
Default

thermostat wiring


Sounds like a bad stat if that is the case.

It's either a bad stat or that the cool wire is not connected to the fan wire, but that doesn't make sense since they both work on manual cool, right? So it must be the stat?
rejames is offline   Reply With Quote
Old 05-02-2012, 05:20 PM   #11
AKA HVACTECHFW
 
Join Date: Nov 2010
Location: NE Indiana
Posts: 2,328
Rewards Points: 1,022
Blog Entries: 1
Default

thermostat wiring


it must be the stat.
__________________
IT IS WHAT IT IS
hvactech126 is offline   Reply With Quote
Old 05-02-2012, 09:07 PM   #12
Member
 
Join Date: Oct 2010
Location: GA
Posts: 163
Rewards Points: 150
Default

thermostat wiring


If there is a local Johnstone supply shop near you.

http://stores.johnstonesupply.com/co...2/Default.aspx

I would go there and pick up a Toptech or Pro1IAQ thermostat. A 701 or 705 should be ok for you as a 1 stage cooling and 1 stage heating. If you have a additional stage of heating then get a 2 stage heating. And wire that one up. It should be pretty straight forward and those are good tstats. Or go to HD and get another honeywell. I like the toptech/pro1iaq , they have a nice big display.

kilosos2 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
2 zone damper 2 thermostat wiring help kostia HVAC 10 08-22-2010 10:57 AM
Thermostat wiring dimbulb HVAC 16 08-20-2010 12:49 PM
Honeywell Prestige HD thermostat wiring 1H/1C + Humidification System TekGamer HVAC 0 07-10-2010 12:58 AM
Unexpected wiring found on existing thermostat mportobello HVAC 12 03-30-2010 07:11 AM
Thermostat wiring question cpuken HVAC 4 12-14-2009 08:32 PM




Top of Page | View New Posts

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