Unlabelled W And R, Will The World Explode? - HVAC - DIY Chatroom Home Improvement Forum


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

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

Reply
 
Thread Tools Display Modes
Old 10-11-2009, 12:57 AM   #1
dtc
Newbie
 
Join Date: Oct 2009
Posts: 5
Rewards Points: 10
Default

Unlabelled W and R, will the world explode?


I'm replacing an old thermostat (manual) which has 2 wires connecting to the heater. Unfortunately, there doesn't seem to be a label on the old thermostat, or the wires.

Questions:

1. Can I assume these two wires are R and W?

2. What would happen if I connected them backwards into my new thermostat (a honeywell RTH700D). Will that cause any damage?

3. If getting this wrong will cause damage, how can I go about determining which one is R and W? (Ideally without accessing the furnace, the door to it is blocked right now by a bunch of other stuff.)

Thanks!

Advertisement

dtc is offline   Reply With Quote
Old 10-11-2009, 06:06 AM   #2
Member
 
biggles's Avatar
 
Join Date: Jan 2008
Location: Long Island
Posts: 3,630
Rewards Points: 2,000
Default

Unlabelled W and R, will the world explode?


R is always RED (hot 24Vs),and W is always WHITE (heat)......you could put the wires together and call the furnace in.if the stat isn't digital and is a generic printed dial face with temps and you set the temp bar ...go for it.if your digital then the RED has to be connected to R on the subbase. you should make a project and clear that stuff from the furnace access...you might not want to do it,but if the system breaks down,and a service guy comes in charging you $100 HR to check it out on a nice 10F night it would be to your benny

Advertisement

biggles is offline   Reply With Quote
Old 10-11-2009, 07:30 AM   #3
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,524
Rewards Points: 4,686
Default

Unlabelled W and R, will the world explode?


Is your new stat battery operated?
beenthere is online now   Reply With Quote
Old 10-11-2009, 11:08 AM   #4
Member
 
Join Date: Dec 2008
Location: West Michigan
Posts: 440
Rewards Points: 250
Default

Unlabelled W and R, will the world explode?


May also need to check the air filter.
SKIP4661 is offline   Reply With Quote
Old 10-11-2009, 11:55 AM   #5
Member
 
Join Date: Sep 2009
Posts: 78
Rewards Points: 75
Default

Unlabelled W and R, will the world explode?


I imagine Beenthere is asking if the system is battery operated is because you need to have a "common" for t-stats that are not battery powered. If you only have two wires coming from the wall, and have no intention of running new wires, you need to have a battery powered stat if you plan on going with programable or digital.

In short, the house will not "blow up" if you reverse the connections. One lead is hot, and the other lead is the heating circuit. A t-stat is simply a switch that senses temperature.Installing a heat only stat is simple, but, you should turn off the power to the heating appliance first. Otherwise you could short out the low voltage circuit.
Flashheatingand is offline   Reply With Quote
Old 10-11-2009, 12:29 PM   #6
dtc
Newbie
 
Join Date: Oct 2009
Posts: 5
Rewards Points: 10
Default

Unlabelled W and R, will the world explode?


Thanks guys. My new thermostat is battery powered and has a computer that claims to think on its own (I expect to eventually become its servant.)

The old one was mercury free - uses a coil.

I was wondering if I could assume that the two wires connecting to the coil were "R" and "W", and was wondering what the consequences would be if I connected "W" to the "R" terminal of the battery powered one, and "R" to the "W" terminal since the wires aren't labeled.
dtc is offline   Reply With Quote
Old 10-11-2009, 04:24 PM   #7
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,524
Rewards Points: 4,686
Default

Unlabelled W and R, will the world explode?


None.
beenthere is online now   Reply With Quote
Old 10-11-2009, 04:30 PM   #8
Hvac Pro
 
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 10,112
Rewards Points: 862
Default

Unlabelled W and R, will the world explode?


You know Max?
yuri is offline   Reply With Quote
Old 10-11-2009, 04:50 PM   #9
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,524
Rewards Points: 4,686
Default

Unlabelled W and R, will the world explode?


Quote:
Originally Posted by yuri View Post
You know Max?
????????
beenthere is online now   Reply With Quote
Old 10-11-2009, 04:52 PM   #10
Hvac Pro
 
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 10,112
Rewards Points: 862
Default

Unlabelled W and R, will the world explode?


Max no difference.
yuri is offline   Reply With Quote
Old 10-11-2009, 05:01 PM   #11
GC/Master Plumber/Mech
 
Join Date: Feb 2009
Location: Hays, KS
Posts: 1,472
Rewards Points: 504
Default

Unlabelled W and R, will the world explode?


Yuri went a fish'n and Been took the bait

__________________
John Wayne once said "Life is tough and it is even tougher if you are stupid"

Tempstar and Trane Dealer
Plumber101 is offline   Reply With Quote
Old 10-11-2009, 05:02 PM   #12
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,524
Rewards Points: 4,686
Default

Unlabelled W and R, will the world explode?


Quote:
Originally Posted by yuri View Post
Max no difference.
ROFL.

ZOOM went right over my head.
beenthere is online now   Reply With Quote
Old 10-11-2009, 05:05 PM   #13
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,524
Rewards Points: 4,686
Default

Unlabelled W and R, will the world explode?


Quote:
Originally Posted by Plumber101 View Post
Yuri went a fish'n and Been took the bait

Hook line and sinker.

Advertisement

beenthere is online now   Reply With Quote
Reply


Thread Tools
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
What is the best paint in the world? Majid Painting 30 06-23-2012 01:28 PM
If Women Controlled The World.... gma2rjc Off Topic 8 04-13-2009 02:51 PM
ICI - Glidden - Color Your World nzan Painting 1 02-27-2008 07:03 PM
World of Wheels Video - Chicago 2007 head_dunce Automotive Repairs 0 01-30-2007 08:49 AM




Top of Page | View New Posts