I just bought a Honeywell 5.2 Day RTH2300B Programmable thermostat to replace my old mercury thermostat for my gas fireplace. When I took of old thermostat it only has two wires. A white wire and a black wire. Can you please let me know how to wire it to the new Honeywell Thank you

You need to remove the thermostat from the wall plate to change the battery. Look on the bottom of the thermostat for a locking screw. Loosen this screw with an appropriate screw driver. Then pull the bottom of the thermostat away from the wall plate and then lift up from the bottom. When you put the thermostat back on, line up the brackets at the top of the thermostat with the slots on the wall plate. Then push the thermostat against the wall plate and tighten the locking screw.

The documentation for the Honeywell RTH2300B1012/U is available on the product page: https://www.honeywellstore.com/store/products/5-2-day-programmable-thermostat-honeywell-rth2300b.htm . Click on the Manuals tab. See page 4 (page 6 of the PDF) for removing the thermostat from the wall plate. See page 9 (11 of the PDF) for replacing the batteries and putting the thermostat back on the wall plate. The current link to the manual is https://www.honeywellstore.com/store/images/pdf/rth2300b1012-u-5-2-day-programmable-thermostat.pdf .

I hope this helps.

Cindy Wells

The Honeywell RTH2300B is not appropriate for any multi-stage heating/coolling system. See https://www.honeywellstore.com/store/products/5-2-day-programmable-thermostat-honeywell-rth2300b.htm . This limitation is the last item listed in the Features section of the thermostat product information.

I hope this helps.

Cindy Wells

Cover the bare end of the C wire with electrical tape so that it doesn't contact any of the other wires or parts of the Honeywell thermostat. The C wire carries continuous power from the red wire to some thermostats; this is required for some of the Smart thermostats (with the ability to communicate with your wireless computer network).

The installation directions for the thermostat include how to handle the C wire when installing the RTH2300B. You can find the manual on the product page in several places, including the Honeywell product site: https://www.honeywellstore.com/store/products/5-2-day-programmable-thermostat-honeywell-rth2300b.htm . The direct link to the manual is https://www.honeywellstore.com/store/images/pdf/rth2300b1012-u-5-2-day-programmable-thermostat.pdf .

I hope this helps.

Cindy Wells

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: https://www.homedepot.com/p/Honeywell-5-2-Day-Programmable-Thermostat-with-Backlight-RTH2300B/203539496 .

Cindy Wells

There is a Honeywell model RTH2300B1012, which is what I think you're talking about.
The Honeywell website has the owners manual for that model available online at:http://customer.honeywell.com/Honeywell/getliterature.axd?LiteratureID=69-2448ES.pdf

New furnace and new thermostat. The new thermostat is digital and it will not go above 67. It's a Honeywell RTH2300.

R--red comming n the thermostat and white is heat going to the furnace!

alot of those gas fireplaces work on what is called powerpyle or 750 mv if your old thermastat has a ts in model then you would need tstat that works with millivolt systems

I connected the blue wire to the R and the white wire to the W on the old thermostat and shoved the new Honeywell 5-1-1 Day programmable thermostat up the first guys *** that i ran into at Canadian Tire

Thanks for your help

try to get one that is made for oil heat, the installation is easy only two wires, and the instructions make it easy.