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Question posted by spazzkatz on August 30th, 2020

How To Change To Celsius

how to change my honeywell rth 6400D to celsius?

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Answer #1: Posted by i96i on September 2nd, 2020 10:56 AM

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i96i

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Hello,

https://www.honeywellhome.com/us/en/support/how-do-i-change-from-fahrenheit-to-celsius-or-celsius-to-fahrenheit

I hope it will help you.

Answer #2: Posted by Odin on August 30th, 2020 11:53 AM

Odin

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Honeywell does not document a facility to make that change. If it's possible, you'll have to consult Honeywell. use the contact information at https://www.contacthelp.com/honeywell/customer-service.

Hope this is useful. Please don't forget to click the Accept This Answer button if you do accept it. My aim is to provide reliable helpful answers, not just a lot of them. See https://www.helpowl.com/profile/Odin.

Answer #3: Posted by chocolatesweetboy30 on September 1st, 2020 3:01 AM

chocolatesweetboy30

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You can change the temperature display by accessing function 14 in the system settings and switching to 1 or 0

Related Honeywell RTH6400 Manual Pages

Owner's Manual - Page 1

Quick Installation Guide RTH6400 Series Programmable Thermostat 69-2210EF-03

Owner's Manual - Page 2

It is Easy Label wires and remove your old thermostat Install and wire your new thermostat Set your new thermostat to match your heating/cooling system - Call 1-800-468-1502 for the most common system We are here to the store. 69-2210EF-03 ii Installation is preset for wiring assistance before returning the thermostat to help.

Owner's Manual - Page 4

If so, see back cover for proper disposal instructions. Old thermostat Cover 69-2210EF-03 2 M28099 2 Remove Old Thermostat Remove old thermostat but leave wallplate with wires attached. Leave wallplate in place Is there a sealed tube containing mercury?

Owner's Manual - Page 6

Wallplate M28343 69-2210EF-03 4 4 Separate Wallplate from new thermostat. Pull here to remove wallplate from New Thermostat Remove battery holder.

Owner's Manual - Page 7

M2834 Thermostat M28344 5 69-2210EF-03 5 Insert Quick Reference Card Insert quick reference card into slot in back of thermostat.

Owner's Manual - Page 10

8 Install Batteries Install two AA alkaline batteries. Back of thermostat M28346 69-2210EF-03 8

Owner's Manual - Page 11

9 Install Thermostat onto Wallplate Install thermostat onto the wallplate on the wall. M28347 9 69-2210EF-03

Owner's Manual - Page 15

SETUP WIRING ASSISTANCE M28348 Press s or t to next function. 13 69-2210EF-03 TROUBLESHOOTING M28349 Press NEXT to advance to change settings. RTH6400 ASybsotuetmyosuertunpew thermostat Press and hold the s and FAN buttons until the screen changes (approximately 5 seconds). Function 1 Setting 0 Done Next Press DONE to exit and save settings.

Owner's Manual - Page 16

When correct setting is selected, press NEXT to change setting. SETUP Advanced Installation Guide Function 1: System type Press the s or t button to select the type of system you have in your... central air conditioning. (Use this setting if you could turn the fan on and off with a fan switch on your old thermostat.) Press to display next function. M28351 69-2210EF-03 14 TROUBLESHOOTING

Owner's Manual - Page 17

... O/B W wire terminal (see page 21). 1 Heating changeover valve: Use this setting if you connected a wire labeled "B" to the O/B W wire terminal (see page 21). SETUP WIRING RTH6400 Function 2: Heat pump changeover valve Press the s or t button to select whether your changeover valve is selected, press NEXT to display next function. ASSISTANCE TROUBLESHOOTING...

Owner's Manual - Page 18

... (system controls fan operation). 1 Electric heat: Use this setting if you have an electric heating system (thermostat controls fan operation). SETUP WIRING Advanced Installation Guide Function 3: Heating fan control Press the s or t button... not appear, please turn to the next page to change setting. When correct setting is selected, press NEXT to display next function. M28351 69-2210EF-03 16

Owner's Manual - Page 19

...% efficiency. 1 Gas/oil steam or gravity system: Use this setting if you have a steam or gravity heat system. M28351 17 69-2210EF-03 TROUBLESHOOTING SETUP RTH6400 Function 5: Heating cycle rate Press the s or t button to select your heating system and optimize its operation: NOTE: If Function 5 does not appear, please turn...

Owner's Manual - Page 20

... display next function. TROUBLESHOOTING Press to option 0 if the outside temperature drops below 50ºF (10ºC). CAUTION: To avoid possible compressor damage, set to change setting. NOTE: System maintains a minimum 3ºF difference between heat and cool settings.

Owner's Manual - Page 21

SETUP WIRING RTH6400 Function 13: Smart Response® Technology Press the s or t button to change setting. M28351 ASSISTANCE TROUBLESHOOTING 19 69-2210EF-03 Press to select Smart Response® Technology: 13 1 Done Next M28356 1 Smart Response® Technology ON 0 Smart ...

Owner's Manual - Page 22

...Advanced Installation Guide AFubnocuttioynou1r4n: eTwemthpermatousrteadt isplay Press the s or t button to select Fahrenheit or Celsius temperature display: 14 0 Done Next 0 Fahrenheit temperature display (°F) 1 Celsius temperature display (°C) M28357 Press to exit and save changes. M28351 ASSISTANCE TROUBLESHOOTING 69-2210EF-03 20 When correct setting is selected, press DONE...

Owner's Manual - Page 23

... page 6). Wrap B wire with electrical tape. 21 69-2210EF-03 Wrap bare end of wire with electrical tape and do not match letters on the thermostat, check the chart below ). Connect O wire to O/B W. Do not use . RTH6400 Wiring If labels do not use C, X or B.

Owner's Manual - Page 24

...set to match your heating equipment (see page 16). Cannot change • Check Function 1: System Type to system setting make sure it is set to acceptable change ranges: • Heat: 40° to 90°F ... Fan Control to make sure it is set to match your thermostat, please try the following suggestions. SETUP WIRING Advanced Installation Guide Troubleshooting If you have difficulty with...

Owner's Manual - Page 25

SETUP WIRING Troubleshooting RTH6400 Heating or • Press SYSTEM button to set system to respond. "Cool On" or "Heat On" is flashing • Compressor protection feature is properly configured ...

Owner's Manual - Page 27

...-1502. Accessories/replacement parts To order, please call Honeywell Customer Care toll-free at 1-800-468-1502. WIRING ASSISTANCE TROUBLESHOOTING 25 69-2210EF-03 Battery holder Part No. 50007072-001 Cover plate assembly Part No. 50002883-001 *Use to cover marks left by old thermostats. To save time, please remove the battery...

Owner's Manual - Page 30

... Printed in a sealed tube. Rev. 08-08 Registered Trademark. D542,677 and other patents pending. © 2008 Honeywell International Inc. 69-2210EF-03 M.S. Contact your old thermostat in the trash if it contains mercury in U.S.A. on recycled paper containing at least 10% post-consumer paper fibers. ® U.S. MERCURY NOTICE: Do not place...