Wiring a Honeywell Room Thermostat

Honeywell thermostat identification photos
Honeywell or Resideo Thermostat Wire Connection Tables
Thermostat Wiring Diagrams -
Thermostat Hook-up Procedures

Honeywell Thermostat Identification Photos & Installation / Wiring Manuals

For most Honeywell room thermostats you can identify the thermostat model by finding its number on the back of the thermostat. As Honeywell put it:

Your [Honeywell thermostat] model number will begin with the letters, T, TH, RTH, C, or CT and is on the back of the thermostat. [5]

Below is our alphabetical list (by model number) of Honeywell / Resideo thermostats where you will fin didentification photographs, wiring manuals (free PDF downloads) and other wiring help.

Honeywell Round Thermostats: T87, T87F, T87K, CT87, CT87 K-N

• HONEYWELL T87F UNIVERSAL THERMOSTAT INSTRUCTIONS [PDF] (2002) - show above - Publication No. 60-0830-4, this is perhaps the most-widely-used Honeywell room thermostat. Instructions include details for setting the thermostat heat anticipator.
  
  Thermostat checkout procedure:
  
  Turn down temperature setting to the lowest point. If subbase or remote switching is used, move system switch to HEAT position. Raise temperature setting until heating equipment starts. This point should be at room temperature as indicated on the thermometer. Slowly turn back dial. Heating equipment should stop when dial has been turned below room temperature.
  
  Mercury notice [Excerpt] This control contains mercury in a sealed tube. Do not place control in the trash at the end of its useful life. ... If you have questions call Honeywell Inc. at 1-800-468-1502.

Honeywell T87F Series Thermostats

• HONEYWELL T87F Thermostat PRODUCT DATA SHEET & CIRCUIT DIAGRAMS [PDF] (2002) - show above
  
  Excerpt:
  Tradeline © Models: For use in series 80 heating, cooling, or heating-cooling circuit, or for use in series 20 (spdt) heating only circuit.
  Tradeline © specifications are the same as those of standard models, except as follows:
  T87F Heating, Cooling, or Heating-Cooling Thermostat.
  T87F Enhanced Setpoint Visibility Model for the visually impaired.
  T87F models that meet Department of Defense (DoD) Manual 4270.1-M specifications.
  Model for heating. control. Locking cover, without thermometer, 72°F (22°C) maximum heat.
  Model for cooling control, locking cover, without thermometer, 78°F 26°C) minimum cool.
  T87F with locking cover, range stops 35°F to 65°F (2°C to 18°C) range.
  
  For the Honeywell T87F Thermostat series see these
  
  detailed WIRING INSTRUCTIONS for Honeywell T87-F THERMOSTATS & their Replacements

• HONEYWELL T87K THERMOSTAT MANUAL [PDF] (2009) CT87K (24Vac heating systems) / CT87N (24Vac heating and cooling systems) - shown above, instructions in English, Francais, Espanol.

Honeywell Round Thermostats: CT87

• HONEYWELL CT87N / CT87K ROUND THERMOSTAT OWNERS MANUAL [PDF] (2009) 69-1959EFS—02 - shown above, retrieved 2016/03/06. CDT87 N/K owners manual in English, Francais, Espanol. Wiring diagrams and installation details.
  
  What's the difference between the CT87N and the CT87K thermostat:?
  
  CT87K is for 24 Vac Heating Systems - if you bought a CT87K and you need it to control both heating and cooling, you'll need to exchange it for a CT87N model.
  
  CT87N is for 24Vac heating and cooling systems - If you bought a CT87N and your home has no central cooling system, you can still ust that thermostat, you simply won't use the cooling control terminals in the thermostat.

• HONEYWELL CT87N Easy-to-See™ THERMOSTAT OWNER'S MANUAL [PDF] 69-1919EFS—06, original source: https://customer.honeywell.com/resources/techlit/TechLitDocuments/69-0000s/69-1919EFS.pdf

Honeywell Round Digital Thermostats T8700B & T8775 A,C

• Honeywell T8700B ELECTRONIC ROUND THERMOSTAT OWNER'S GUIDE [PDF] (1998) - shown above. This thermostat does not require batteries; time and temperature settings are held permanently in memory.
  
  This thermostat is also discussed at THERMOSTAT SETTING INSTRUCTIONS
  
  and at RADIANT HEAT TEMPERATURE NIGHT SETBACK
• Honeywell T8700B,C ELECTRONIC ROUND PROGRAMMABLE THERMOSTAT PRODUCT DATA [PDF] (1998) more information for the T8700 B / T8700C thermostat shown above.
  
  Excerpt: The T8700 Electronic Round™ Programmable Thermostats provide single-stage, programmable temperature control for 24V heating and/or cooling systems.
  
  The T8700B model T8700B1007 is a heat-only thermostat with no fan control. Use wiring terminals R, W.
  
  The T8700B model T8700B1015 is also a heat-only thermostat that includes a Fan ON-AUTO feature suitable for forced warm air furnace heating systems. Use wiring terminals R,G,W.
  
  The T8700C model T8700C1005 provides control of both heating and cooling (air conditioning or heat pump) and also includes a fan ON-AUTO feature. Use wiring terminals R,G,W,Y.
  

• HONEYWELL T8775A,C DIGITAL ROUND NON-PROGRAMMABLE THERMOSTAT INSTALLATION & WIRING MANUAL [PDF] (2004) Digital Round T8775 - CT8775A1007 - Non-Programmable - show above , Owner's Guide, retrieved 2018/10/07, original source: https://customer.honeywell.com/resources/Techlit/TechLitDocuments/69-0000s/69-1679ES.pdf
  
  The manual above also applies to the Honeywell T8775A1009/U and to the T8775A1017/U

Honeywell DT92E Wireless Thermostat

Honeywell Focus Pro TH6110 Series Thermostats

• HONEYWELL FocusPRO TH6110D PROGRAMMABLE THERMOSTAT INSTALLATION GUIDE [PDF] (2005) Installation Instructions for the Honeywell TH6110D & Honeywell TH6220D thermostats - show above
  
  Excerpt:
  This thermostat provides electronic control of 24 VAC single-stage heating and cooling systems, or 750 mV heating systems.
  
  Also see the User's guide for this same thermostat, just below.

...

Illustration above: wiring terminals for the Honeywell TH611 Thermostat

• HONEYWELL FocusPRO TH6110D / TH6220D OPERATING MANUAL [PDF] (2005) Programmable Thermostat Operating Manual - the User's Guide - show above
  
  Also see the TH6110D installation manual for this thermostat, give above on this page.

Honeywell Lyric Round WiFi Thermostat

• HONEYWELL Lyric Round™ WI-FI THERMOSTAT INSTALLATION GUIDE [PDF] (2015) - show above, retrieved 2020/01/16 original source: https://forwardthinking.honeywellhome.com/related_links/thermostats/lyric/Professional_Installation_Guide.pdf
  
  Excerpt: Compatible with 24-volt systems such as forced air, hydronic, heat pump, oil, gas and electric.
  
  Does not work with electric baseboard heat (120/240V).

Honeywell RTH-Series Programmable Thermostats

• HONEYWELL RTH 2300 / RTH221 Series THERMOSTAT MANUAL [PDF] (2015) Programmable thermostat for gas, oil, electric furnace, air conditioners, hot water with or without pump, millivolt systems, central heating & cooling, heat pump without auxiliary or backup heat - show above
  
  The RTH2300 thermostat can NOT be used on heat pumps with backup heat nor on multistage systems.

• HONEYWELL RTH3100C THERMOSTAT INSTALLATION & WIRING MANUAL [PDF] manual,(2008) retrieved 2017/09/17, original source: https://customer.honeywell.com/ resources/ techlit/TechLitDocuments /69-0000s/69-1889EF.pdf
  
  Also see these
  
  HONEYWELL RTH3100C THERMOSTAT INSTALLATION & WIRING TABLES & NOTES - wiring connections for the RTH3100C Thermostat

• HONEYWELL RTH4300B THERMOSTAT MANUAL [PDF] (2006) - shown above

• HONEYWELL RTH6350 / RTH 6450 THERMOSTAT INSTALLATION & WIRING NOTES for the thermostat shown above, also support for the Honeywell RET93E / RET95E series thermostats
• HONEYWELL RTH6350 / RTH6450 THERMOSTAT INSTALLATION GUIDE [PDF] retrieved 2017/12/26, original source: https://customer.honeywell.com/resources/techlit/TechLitDocuments/69-0000s/69-2416ES.pdf
• HONEYWELL RTH6350 / RTH 6450 and RET93E / RET95E Series Thermostats INSTALLATION & OWNERS MANUAL [PDF] retrieved 2017/12/26, original source: https://customer.honeywell.com/resources/techlit/TechLitDocuments/33-00000s/33-00116ES.pdf
• HONEYWELL RTH6350 / RTH6450 Series THERMOSTAT OPERATING MANUAL [PDF] does not include wiring instructions, retrieved 2017/12/26, original source: http://pdf.lowes.com/useandcareguides/085267573672_use.pdf

Honeywell T6 Pro Thermostat Series

• HONEYWELL T6 Pro PROGRAMMABLE THERMOSTAT INSTALLATION INSTRUCTIONS [PDF] (2018) Honeywell TH6210U2001 thermostat manual - show above

• HONEYWELL T6 Pro Z-Wave THERMOSTAT MANUAL [PDF] (2022) Programmable Thermostat TH6320ZW2003 User Guide - shown above
• Honeywell T6 Pro Z-Wave THERMOSTAT USER GUIDE [PDF] (2016)

Honeywell T6169 Fan Coil Line Voltage Thermostat

• HONEYWELL T6169 FAN COIL THERMOSTAT MANUAL [PDF] (2001) This is a line voltage thermostat - show above. Retrieved 2020/01/16 original source: https://customer.honeywell.com/resources/Techlit/TechLitDocuments/95C-00000s/95C-10679.pdf
  
  Excerpt: The T6169 thermostats control line voltage valves an/or blower motors on Fan Coil units in manual or automatic changeover, cooling, heating or cooling/heating systems.
  
  These thermostats feature single fan an/or system manual switches.

Honeywell T6811 Digital Thermostat

• Honeywell T6811DP08/T6812DP08 DIGITAL THERMOSTAT INSTRUCTION MANUAL [PDF] (2009) - show above

Honeywell T7350 Digital Heat Pump Thermostat

• HONEYWELL T7350 Programmable Thermostat FOR CONVENTIONAL / HEAT PUMP SYSTEMS [PDF] (2006) - show above
  
  Excerpt: Typically used in buildings (including: restaurants, shopping malls, office buildings and banks) under 55,000 square feet. ï For single zone rooftop units, split systems, heat pumps or hot/chilled water systems.

Honeywell TB6980 / 7980 Zone Pro Thermostats

• Honeywell TB6980 / TB7980 THERMOSTAT MANUAL [PDF] (2012) ZonePRO Thermostats
  
  The TB6980/TB7980 digital thermostats provide proportional plus integral individual space temperature control in zoned commercial HVAC systems such as hydronic and pressure dependent VAV with or without reheat.
  
  There are four different models:
  
  TB7980A (single output, modulating)
  
  TB6980A (single output, floating)
  
  TB7980B (multiple output modulating)
  
  TB6980B (multiple output, floating)

Honeywell TB7100 Multipurpose Thermostat

• HONEYWELL TB7100A1000 MultiPRO™ Multispeed and Multipurpose Thermostat INSTALLATION & WIRING MANUAL [PDF] (2011) - show above retrieved 2018/10/07, original source: https://customer.honeywell.com/resources/techlit/TechLitDocuments/62-0000s/62-0273.pdf

Honeywell TH8320 / 9320 WiFi Thermostat

• HONEYWELL TH8320ZW TT MANUAL [PDF] (2013) Installation Guide - show above

• HONEYWELL TH9320WF5003/U WiFi 9000 Series WIRING NOTES - Color Touchscreen Thermostat instructions, wiring connections, setup guide, copy of the TH9320WF5003/U Manuals [PDF]
• HONEYWELL TH9320 Wi-Fi Thermostat Color Touchscreen INSTALLATION MANUAL  [PDF] (2016) retrieved 2017/09/18 original source: https://customer.honeywell.com/resources/Techlit/TechLitDocuments/69-0000s/69-2815EFS.pdf

Honeywell W8735 Outdoor Reset Module

• HONEYWELL W8735E-INSTALLATION-MANUAL [PDF] (2012) Wireless Outdoor Reset Module - show above
  Excerpt:
  The W8735ER Wireless Outdoor Reset Module, when connected to the C7089R1013 Wireless Outdoor Sensor, works with any AquaReset enabled Aquastat® such as the L7224/48 Aquastat, S9360/61/80 Integrated Boiler Control, and R7910 SOLA Control via the EnviraCOM™ 3-wire bus.
  
  The Wireless Outdoor Reset Module enables efficiency control functionality, such as Outdoor Temperature Reset, Boost function, and Warm Weather Shutdown function to generate average operational savings of up to 15%.
  

Honeywell 9000 WiFi Thermostat

• HONEYWELL Wi-FI Thermostat 9000 INSTALLATION GUIDE [PDF] (2016) - show above, retrieved 2020/01/16 - shown above, original source: https://customer.honeywell.com/resources/Techlit/TechLitDocuments/69-0000s/69-2815EFS.pdf

How to Wire the Two-Wire Honeywell CT-87, & T8775X - Heat Only or Cool Only

Shown above is the company's original traditional T87 round non-programmable thermostat and below its contemporary, digital replacement, the Honeywell's T8775C1005.

Both of these thermostats will be wired the same way.

How to Wire a typical Two-Wire Honeywell T87-F type Wall Thermostat

Notes to the table above

Honeywell thermostat T87F type models include the Super Tradeline T87F1959 (replaces the T26A1433 and T87C1252), T87F1867, T87F2816, T87F2824, T87F2873

These thermostat T87F models vary by the operating temperature range they support and a few other simple features such as the presence or absence of a thermometer. Functionally and for wiring they are similar.

You will find only 2 wires in-use at the wall thermostat if it is used for Heat only or for Coolilng only. There may be other un-used thermostat wires in the wiring bundle.

1. The [Honeywell 5-2 Day Programmable Thermostat - RTH2300B1012] thermostat cannot be used if your old thermostat had [and used] any two of the following wires: R, RC, RH, 4 and V.[5]

2. If your single-use thermostat is supporting a heat-only or cool-only system and has just a single R wire, most straighforward would be to connect the wire to the Rh if you are heating or to Rc if you are cooling.

3. If you're still uncertain about your thermostat wiring, see this chart that identifies all of the thermostat wiring terminals and color codes - THERMOSTAT WIRE TERMINAL ID CODES / FUNCTIONS 

Also see these other HONEYWELL T87 WALL THERMOSTAT WIRING DIAGRAMS

Simple Honeywell T87F Thermostat Wiring: Red & White Wires, Heat Only

How to Wire the Three-Wire Honeywell Wall Series 20 Thermostat, CT-87, & T8775X

Notes to the table above

1. Also see these other HONEYWELLT87 WALL THERMOSTAT WIRING DIAGRAMS - Honeywell Wall T87-F type Thermostats for sketches and drawings of Honeywell thermostat wiring hookups.

2. Watch out: For Honeywell Wall Series 20 type Thermostats connect the white wire coming to the thermostat from the heater or air conditioner to the (Y) terminal, not the (W) terminal.

Simple Honeywell T87F Thermostat 3-Wire Hookups: Red, Yellow & White Wires, Heating & Cooling

Simple Honeywell T87F Thermostat Wiring: Red & Yellow Wires, Cooling Only

Wire or Repair the Honeywell the 5-2 Day Programmable Thermostat - RTH2300B1012

Notes to the table above

If you're having trouble getting your thermostat to work, note the following:

1. Watch out: This thermostat cannot be used if your old thermostat had [and used] any two of the following wires: R, RC, RH, 4 and V.
2. Do not use C, C1 or X wire. Do not use B wire if you already have O wire. Wrap bare end of wire with electrical tape.
3. Place a jumper (piece of wire) between Y and W if you have a heat pump without auxiliary/back-up heat.
4. HONEYWELL RTH2300/RTH221 SERIES PROGRAMMABLE THERMOSTAT OWNERS MANUAL [PDF]
5. Other methods for identifying thermostat wires and to what they are connected are
   
   at THERMOSTAT WIRING COLOR CODES and
   
   at THERMOSTAT WIRE TERMINAL ID CODES / FUNCTIONS
6. Watch out: while we describe thermostsat wire identification and use by color, when replacing an older thermostdat or workign on an older building, don't assume that workers before you followed the same wire color conventions. Follow wires back to their connections to see where they were used and watch for splcies in wires enroute that might change colors!

Troubleshooting the Honeywell 5-2 Day Programmable Thermostat - RTH2300B1012

Remember that ultimately a thermostat is simply an on-off switch, or provides several on-off functions. But with multiple zone heat, you should expect to provide a thermostat for each individual zone - or else they're not heating zones at all.

In a traditional hot water heating system that does not use the Azel i-Link controller, the first thermostat is wired directly to an aquastat that controls the first zone; the second two thermostats are wired to individual circulator relays (if individual circulator pumps are used) or to individual zone valves (if a single circulator runs the whole system).

Where zone valves are used, an end switch closes to turn on the circulator (a logical inclusive OR function with the other zone valves) when the zone valve opens to allow hot water to flow. That same principle is used when wiring the Azel i-Link Zone Switching Relay.

And the company makes clear that their controller is compatible with standard thermostats:

ALL - controls are compatible with 2, 3 or 4 wire type thermostats. 24VAC output can be used to supply power to the thermostat. For thermostats requiring the 24VAC Common, simply connect C terminal from the thermostat to COM terminal on the 24VACoutput.[4]

First let's make sure you've identified your Honeywell thermostat model correctly.

Your [Honeywell thermostat] model number will begin with the letters, T, TH, RTH, C, or CT and is on the back of the thermostat. [5]

Honeywell RHT2300B - the number you gave, doesn't look right, but you probably meant RTH-2300-B. Calling Honeywell with the right product number (Tel: 800-468-1502) might produce better results. Honeywell has done a great job making installation and operations manuals available for their equipment, but you've got to search with the right product number.

Searching the Honeywell site for the corrected thermostat number delivers a single product that's probably yours, the 5-2 Day Programmable Thermostat - RTH2300B1012.

In fact this thermostat is widely sold including at Home Depot stores, and I've installed and used this very model myself to control an add-on hot water heating zone and Taco circulator in an older home. According to Honeywell, this thermostat is compatible with:

• Gas, oil or electric furnace
• Central air conditioner
• Millivolt system
• Central heating and cooling system
• Heat pump without auxiliary/backup heat. (This thermostat cannot be used on heat pumps with auxiliary heating or on multistage systems.)

For your model you want Honeywell document 69-2326ES - found at http://customer.honeywell.com/Honeywell/getliterature.axd?LiteratureID=69-2326ES.pdf - owners operation manual or

document 69-2327ES - for installation materials - found at
http://customer.honeywell.com/Honeywell/getliterature.axd?LiteratureID=69-2327ES.pdf

Here are details from that manual's instructions for wiring the Honeywell RTH-2300-B 5-2 Day Programmable Thermostat beginning with the inspection of the existing wires:

How to Correctly Identify the existing thermostat wires

3. Identify and label each of the existing thermostat wires by using not the wire colors (someone could have made a wire color error and violated convention) but rather, identify each existing thermostat wire by noting the letter next to the old thermostat wiring block terminals where each wire was connected to a screw. Identify and label the wires that are connected as

• R (convention would be red wire)
• W (convention would be white wire)
• Y (convention would be yellow wire)
• G (convention would be green wire)
• C (convention would be "common" wire, usually a black wire)

If any wires are not attached to your old thermostat or are attached to a terminal marked C or C1, they will not be connected to your new thermostat. Wrap the bare metal end of each of these wires with electrical tape, so it cannot touch and short other wires.

Watch out: since here we are focusing on connections, I am leaving out some important procedure and safety details like removing and taping each wire end to avoid shorting, etc. so be sure to consult the installation manual in detail.

On your new thermostat, the Honeywell the 5-2 Day Programmable Thermostat - RTH2300B1012, connect the wires you labeled as follows:

• Wire labeled R (convention would be red wire) is connected to the "R" terminal on the thermostat
• Wire labeled W (convention would be white wire) is connected to the "W" terminal on the thermostat
• Wire labeled Y (convention would be yellow wire) is connected to the "Y" terminal on the thermostat
• Wire labeled G (convention would be green wire) is connected to the "G" terminal on the thermostat
• C (convention would be "common" or black wire) - you won't use this on the new thermostat

Honeywell RTH3100C Thermostat Installation & Wiring

Below Honeywell shows the typical wiring connections or the RTH3100C thermostat.

Be sure that you label the wires before disconnecting them from the old thermostat, or if you are installing new equipment, identify the incoming wires from the equipment terminals and its manual.

Below are alternative wiring connections for the Honeywell RTH3100C thermostat along with an explanation.

Below is the complete Honeywell RTH3100C thermostat installation manual in PDF format.

• HONEYWELL RTH3100C THERMOSTAT INSTALLATION & WIRING [PDF] manual,(2008) retrieved 2017/09/17, original source: https://customer.honeywell.com/ resources/ techlit/TechLitDocuments /69-0000s/69-1889EF.pdf
• Contact Honeywell for Assistance in wiring by Telephone: 1-800-0468-1502, or Website: http://yourhome.honeywell.com

Honeywell RTH6350/ RTH6450 & RET93E / RET95E Thermostat Installation & Wiring Guide

The Honeywell RTH6350 uses the following wire connections:

Basic RTH6350 / 6450 Wire Connections

• Green wire(G) to G terminal on the thermostat
• White wire (W) to the W terminal
• Yellow wire (Y) to the Y terminal
• Red wire (R) to the R terminal, with this note: remove the factory-installed jumper between R and RC IF you have both an R wire and an RC wire (that you should have identified and labeled from your old thermostat hookup).

Alternate RTH6350 / RTH6450 RET93E / RET95E Wire Connections

• C / X / B - do not connect - tape off bare wire ends
• Y2 wire to Y2 terminal on the thermostat wiring bus bar
• W2 wire to W2 terminal
• G or F wire to G terminal
• W or W1 or H wire to W terminal
• Y or Y1 or M wire to Y terminal
• Rh, 4 or V wire to R terminal, after removing factory-installed metal jumper between R and Rc
• Rc or R wire to Rc terminal, after removing factory-installed metal jumper between R and Rc

Watch out: if your wires do not match the above see several alternative wiring installation hookups on both of the thermostat wiring manuals given just below.

HONEYWELL RTH6350 / RTH6450 THERMOSTAT INSTALLATION GUIDE [PDF] retrieved 2017/12/26, original source: https://customer.honeywell.com/resources/techlit/TechLitDocuments/69-0000s/69-2416ES.pdf

HONEYWELL RTH6350 / RTH 6450 and RET93E / RET95E Series Thermostats INSTALLATION & OWNERS MANUAL [PDF] retrieved 2017/12/26, original source: https://customer.honeywell.com/resources/techlit/TechLitDocuments/33-00000s/33-00116ES.pdf

HONEYWELL RTH6350 / RTH6450 Series THERMOSTAT OPERATING MANUAL [PDF] does not include wiring instructions, retrieved 2017/12/26, original source: http://pdf.lowes.com/useandcareguides/085267573672_use.pdf

Wiring the Honeywell RTH6350 to replace a 3-wire White Rogers thermostat

Our reader asked:

Hi, I have a setup that I think is probably common, at least in the northeast, but that I found very difficult to get straight.

I have a boiler with a hydronic zone valve that controls two zones. The thermostat I was replacing was an old White-Rogers mercury switch. It's a 3-wire configuration. The new t-stat is Honeywell RTH6350.

Both thermostats are wired into the hydronic valve. The valve connectors are labeled with numbers 1-6.

The wires going to the T-stat I replaced were configured like so:

• the Red wire is attached to 4, on the White Rodgers Thermostat
• the White to 5, and
• the Green to 6.

My final, working configuration for the Honeywell RTH6350 thermostat is:

• White-5 from the hydronic valve to ROn the t-stat
• Red-4 to W
• Green-6 to Y

I had some trouble getting through to Honeywell support, but I finally succeeded in communicating with someone via the live chat they offer at the bottom of their help and support page.

That worked well. One tip before using that service: start the chat on a laptop or mobile device; I was on a desktop and had to run up and down the stairs checking on wiring.

I never would have arrived at that on my own given the information in the t-stat manual and what I've found on the internet, so bravo Honeywell support person. (Oct 4, 2017) Ryan

Honeywell TH9320WF5003U Thermostat Installation & Wiring

• HONEYWELL TH 9320 Wi-Fi Thermostat Color Touchscreen INSTALLATION GUIDE [PDF] retrieved 2017/09/18 original source: https://customer.honeywell.com/resources/Techlit/TechLitDocuments/69-0000s/69-2815EFS.pdf
• HONEYWELL TH 9320 Wi-Fi Thermostat Color Touchscreen USER SETUP INSTRUCTIONS [PDF] retrieved 2017/09/18 original source:
• Contact Honeywell for Assistance in wiring by Telephone: 1-800-0468-1502, or Website: http://yourhome.honeywell.com

How to use the blue wire on the Honeywell TH9320WF5003U

Reader question:

I previously had a Source1 tstat. Battery powered. No issues. I decided to upgrade to a programmable tstat. I went with the Honewell TH9320.

The wiring was the same W to white, Y-yellow, and G- green. I hooked up the Red to R (previously it was hooked to the RC-RH loop).

There was an additional blue wire that was not used, but I needed now for the 24volt power.

I hooked the Blue-wire up on the control board. Now, as soon as I connect the tstat, the blower kicks on.

I have it set to auto. Even if i turn it off, it still runs. Only way to turn off the blower is to disconnect the tstat or unplug the blower.

I turned the temp up to 80 in my house. the tstat read 73, and stayed running. (this is the AC).

Do these units take time to sync, or anything?

Should I let it run longer? Or is my tstat defective? I hooked my old source1 back up and it is fine. turns on and off when temp is reached. 2017/09/18, Marc

Reply: the Blue wire is typically used for a heat pump reversing or "changeover" valve, not as a standard power source

Marc,

First, did you confirm what the blue wire is doing in your wiring harness?

In the Honeywell TH9320 installation manual, as I read the wiring instructions they expect the blue wire to be operating a reversing valve - for heat pumps.

And in setup you are to "In Setup, set changeover valve to O or B."

Usually the R (red) wire or Rc wire is the power source to the thermostat and carries 24VAC.

In the thermostat Custom Setup did you make sure that your thermostat is set for the proper type of heating system:

Your system type Select Forced Air (default), Heat Pump, or Hot Water or Steam. Each option offers different choices on the following screens.

Your forced air heating system type Select how your forced air system is powered: Gas/Oil (default) or Electric.

Efficiency of your heating system - Select Standard Efficiency Forced Air (default) or High Efficiency Forced Air.

Your heating system type - If you selected Hot Water or Steam on “Your system type,” select the specific heating system here. Note: Touch the orange Help button on any screen for more information.

Number of cooling stages Select 1 Stage (default) or 2 Stages. If you are unsure, note which wires are connected: ‘Y’ wire only (1 stage) or ‘Y’ and ‘Y2.’

Number of heating stages Select 1 Stage (default) or 2 Stages. If you are unsure, note which wires are connected: W’ wire only (1 stage) or ‘W’ and W2.’

Your fan control Select whether your thermostat (default) or heating system controls the fan.

Type of changeover valve - If you selected Heat Pump on “Your system type,“ select whether it uses a cooling changeover valve (default) or heating changeover valve. If you are unsure, note which wires you have connected.

Number of heat pump compressor stages

Select 1 Stage (default) or 2 Stages. If you are unsure, note which wires are connected: ‘Y’ wire only (1 stage) or ‘Y’ and ‘Y2.’

Your backup heat No or Yes (default) you can determine whether you have backup heat.

Older Honeywell Thermostat Wiring Diagrams

• 2-WIRE GAS HEAT HONEYWELL THERMOSTAT WIRING DIAGRAM
• 2-WIRE OIL HEAT HONEYWELL THERMOSTAT WIRING DIAGRAM
• 3-WIRE HIGH LIMIT HONEYWELL T87F THERMOSTAT WIRING DIAGRAM
• 3-WIRE SPDT HONEYWELL T87F THERMOSTAT WIRING DIAGRAM
• 4-WIRE HONEYWELL RTH2300 PROGRAMMABLE THERMOSTAT WIRING DIAGRAM

2-Wire Gas Heat Honeywell T87F Thermostat wiring diagram

At left the thermostat wiring diagram illustrates use of a Honeywell T87F thermostat in a 2-wire application controlling a gas fired heating appliance.

In the Honeywell T87F thermostat series the single pole double throw switch makes (closes) one set of contacts when the temperature falls - to turn on the heating appliance.

A second set of contacts will make or close on temperature rise. This second set of contacts is typically used to operate a cooling or air conditioning system but may also be used to operate other controls or valves in some heating systems.

2-Wire Oil Heat Honeywell T87F Thermostat wiring diagram

Above the thermostat wiring diagram illustrates use of a Honeywell T87F thermostat in a 2-wire application controlling an oil fired heating appliance.

For a table of wiring connections for this thermostat also see

• TWO-WIRE HONEYWELL T87-F TYPE WALL THERMOSTAT WIRING - wiring details
• HONEYWELL CT87A,B,J ROUND® THERMOSTAT LOW VOLTAGE (15 TO 30 VAC) THERMOSTAT AND MOUNTING HARDWARE INSTALLATION INSTRUCTIONS (2002) [PDF]
• HONEYWELL T87F THERMOSTAT PRODUCT DATA SHEET & CIRCUIT DIAGRAMS [PDF] (2002)

3-Wire High Limit Honeywell T87F Thermostat wiring diagram

At left the thermostat wiring diagram illustrates use of a Honeywell T87F thermostat in a typical 3-wire, open contact, high limit control such as on an oil fired heating boiler.

3-Wire SPDT Honeywell T87F Thermostat wiring diagram

At left the thermostat wiring diagram illustrates use of a Honeywell T87F thermostat in a 3-wire application as a spdt (single pole double throw) switch such as used to control low voltage motors, electric radiator valves, zone valves.

The thermostat makes a contact on both a rise and on a fall of room temperature.

4-Wire Honeywell RTH2300 5+2 Programmable Thermostat wiring

At left the thermostat wiring diagram illustrates the typical wiring connections when installing a Honeywell RTH2300 (or similar) programmable room thermostat. Be sure to identify and label the existing thermostat wires before disconnecting them from the terminals on the old thermostat you are replacing.

Watch out: existing thermostat wires that will not be used in the new thermostat installation, such as wires attached to C or C1 terminals on the old thermostat should have their ends taped so as not to accidentally touch and short other thermostat wires or connectors.

Here is a copy of the HONEYWELL RTH2300/RTH221 SERIES PROGRAMMABLE THERMOSTAT OWNERS MANUAL [PDF]

Need More help? Call Honeywell at 1-800-468-1502 for assistance with your Honeywell thermostat.

Honeywell Series 10 Thermostats & Controls - R19A thermostat

Honeywell Series 10 controllers such as the Honeywell R19A use a simple relay and built-in transformer and one or more line voltage contactors.

These are spst switch type controls (such as heat-only).

The No. 1 is a low voltage holding contact while the No. 2 is a line voltage contactor. The "coil" shown may be a magnetic coil that pulls in the armature of the No. 1 relay or it may be a relay type coil used in a gas control valve. The holding contact closes when the coil is energized.

In this sketch from a 1949 Honey Heating Control Handbook the thermostat has been satisfied (both contacts are open) and the system is not calling for heat. On a drop in temperature the flexible blade makes the white contact, and subsequently connects the stiff blade. On a rise in temperature the contacts break (or open) in the opposite order. [Line voltage circuits are not shown].