Question about Honeywell Programmable Thermostat Heater

1 Answer

Where is the common on rth 6350/6450 series, have extra red wire hvac says it needs to plug into a common

Posted by on


1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.


    An expert whose answer got voted for 500 times.

  • Master
  • 1,654 Answers

The common is the ground. This can be hooked to the green wire from electric supply or grounded to the cabinet in the unit if the unit is grounded.

Posted on Mar 20, 2011


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Digital thermostat Honeywell RTH 2300 - compressor runs when in heat mode

Check thermostat wires maybe to long and touching in the back of the thermostat

Mar 21, 2013 | Heating & Cooling

1 Answer

I installed the RTH 230B thermostat, Theheat only works when set to the cool mode, I only have gas furnace(no ac unit). My old wires are Red, white, green and blue. What wires go where?

Hey jim Try....RH/RC jumper (connected with a small piece of wire)...RH/RC=RED...W=WHITE...G=GREEN blue=unused... should give heat only (in heat mode) no ac..tks

Nov 12, 2011 | Honeywell Programmable Thermostat Heater

1 Answer

I am trying to replace a Honeywell thermostat model #T87F with a model RTH 111, which Honeywell advises is compatible. After following all instructions, I have cooling, but no heat. This is a one zone...

Hi, Have you jumpered Rc and Rh??? I bet you just have the red wire under the Rc terminal only...heat goes on when power goes from Rh to W... the white wire should be on W and energized (24v) when the t-stat is calling for heat...

Here is a list of each common terminal and what their commonly used for. Alsolisted is what colors are commonly used. NEVER ASSUME these are what youhave. Verify all your wires by following each to each piece of equipment. Thiswill help you to be able to match your equipment with the terminal.

Here is the rest of the tip that I wrote...

Thermostat Wiring and Terminal Designations

Aug 23, 2011 | Honeywell Heating & Cooling

1 Answer

Honeywell RTH 7500d is not working.

If nothing is happening then I am wondering about tje power... If you have access to a digital meter, you should have 24v a/c across the R wire and the C wire...
Did you make sure to turn off the power at the air handler or furnace before unhooking the wires at the t-stat??? If not then you have blow a fuse in the control board or burnt out the transformer...

If you have power on R then jumper to G and the fan shoudl come on... if it does then the t-stat is bad...

This should give you a few things to try and is what I would be doing if it were my service call...


Apr 29, 2010 | Honeywell CT87B ROUND HEATING&COOLING...

1 Answer

Have two wires disconnected from a carrier hvac unit that goes to supply air fan. they are 4 wires total. one yellow goes to l2 on circuit board and red to bm, the black and blue wire is not connected...

Hi, these wires control the speed of the blower motor.L-2 is one power leg and red to bm (blower motor). If the other 2 wires are wire tied out of the way, and they have always been this way, that's the way they come from the factory, to control different speeds. On a 230 volt blower motor, you will see a yellow which normally goes to L-2 on the board. Then you will have a black, red, and sometimes blue. Sometimes you will see L-2 with yellow, L-1 could be any one of the other colors as they are marked on the motor. Low, Med, and High speed are what these extra wires are for. So, you are only using 1-speed. If it is running, and has been, forget the other 2 wires. If its not working, look for a L-1 on the board and connect any one of the other 2 wires. Like I said though, if this is always how its been and running fine, this is a normal termination. Let me know if you have a motor problem, and I can walk you through it.
PS The BM red wire is L-1 on the board.

Dec 04, 2009 | Carrier XHB123D X/Y Series Heat/Cool Air...

1 Answer

I just purchased a honewell RTH 221 thermostat. I

Typically the four thermostat wires are:

R = power (or common)
W = Heat
Y = Cool

Assuming that you have a normal electric or gas furnace and air conditioning, if the heat really is coming on, then just switch the position of the the Yellow and White wires.

Nov 02, 2009 | Honeywell Programmable Thermostat Heater

1 Answer

How to hook up Honeywell rth 7600. have an extra wire

From what I'm seeing the 7600 is not compatible with a heat pump. Where are you landing the orange wire?

May 12, 2017 | Honeywell Heating & Cooling

1 Answer

Y1 W1 Wire from older Honeywell to new RTH honeywell

Y1 means for cool and W1 means for heat. Connect accordingly.

Aug 11, 2008 | Honeywell Programmable Thermostat Heater

Not finding what you are looking for?
Heating & Cooling Logo

Related Topics:

234 people viewed this question

Ask a Question

Usually answered in minutes!

Top Honeywell Heating & Cooling Experts

Bill Long

Level 3 Expert

588 Answers

Paul Carew

Level 3 Expert

3280 Answers

vance jones

Level 2 Expert

120 Answers

Are you a Honeywell Heating and Cooling Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides