Honeywell Heating & Cooling - Recent Questions, Troubleshooting & Support

up arrow and fan simultaneously until screen changes. down to option 13, change to zero not 1

Honeywell... | Answered on Sep 16, 2018

To test if tstat is bad, remove the face plate. Turn power off and put red and green together and resume power. your blower should run. if it does the tstat is bad

Honeywell... | Answered on Sep 16, 2018

You are not reading the manual. Even professionals have to read the manual. You likely are not in programming mode in the first place.

If you need further help, reach me via phone at

Honeywell... | Answered on Sep 15, 2018

The time may have to be reset following a power outage.

Honeywell... | Answered on Sep 09, 2018

page 13 . Look at home depot Lowe's for similar models as this is not made anymore (you can buy used from eBay.
Model # RTH221B is $28.00. According to your model number it is a standard 24 VAC thermostat. You can pick from several models and prices, but the I showed is the closest to yours

Honeywell... | Answered on Sep 08, 2018

The Honeywell RT2300/RTH221 do not work with most baseboard heating systems. The thermostat works with 24V heating systems. Most baseboard systems are 120V or 240V.

I wish that I had better news for you. You can see the specifications at the Home Depot product site (for one version of the RTH2300) here: .

Cindy Wells

Honeywell... | Answered on Sep 07, 2018

press and hold up and down arrows until screen changes. Function 1 should be changed FROM 0 to 1

Honeywell... | Answered on Sep 03, 2018

have you read the manual?

Honeywell... | Answered on Sep 02, 2018

Keep in mind you have the same terminals on the damper. 1-4-6. be sure both board and dampers are wired the same for spring open/power closed. I cant remember if that 311 sends power with a call or not( if power is being sent when light is on), but once you have double checked the damper wiring either verify with a meter that power is being sent or verify air flow. if it is then backwards simply reverse wires on board. I suspect it sends power when light is on, that is why zone 3 is lit. (there is no call for cooling on 3, therefore it is shutting the damper) YES, the damper that is not really there. Let me know, hope this helps. The damper that is trying to cool should NOT be getting any power, wire accordingly.

Honeywell... | Answered on Sep 02, 2018

Since there are no manuals on line I would probably say there are screws on the back and bottom of the unit to take it apart? It should be taken apart by a professionals

Honeywell... | Answered on Aug 31, 2018

What kind of unit is this attached to. Furnace, Electric or Gas or Heat pump?

Honeywell... | Answered on Aug 31, 2018

What kind of unit is this attached to? Gas furnace Heat pump? residential or commercial. I cannot find anything on this old of thermostat.

Honeywell... | Answered on Aug 31, 2018

Page 13 of instruction manual

Honeywell... | Answered on Aug 28, 2018

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