I am installing honeywell rth221 to an old 2 wire system. How do I do this

Contact Support direct.
https://www.honeywellhome.com/us/en/support/air/thermostats/product-selector/device-not-working/

https://www.google.com/search?q=Honeywell+RTH221+thermostat.+How+to+calibrate

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Model #RTH6360D1002
Model #RTH7560E1001/E
check for these at HD or lowes, you will t stat with aux or emergency heat.

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

are you running a program?

If you need further help, reach me via phone at https://www.6ya.com/expert/thomas_092728000e6acb79

First things first. What type of system? Heat only, boiler or furnace? Central cooling.
Do NOT take wires off the old thermostat yet, or mark the color wire, to the terminal letter. Most times W,Y,G,R, terminals and maybe even a C terminal.

Your new thermostat should have the same letters. Sometimes they mix up color wire with terminal letters...... example (yellow wire to w terminal)
Also turn off power to equipment it is controlling. It is not high volts but you can short out the transformer. Hook uo wire color to same letter terminal on old stat, to new stat. Thats it.

http://customer.honeywell.com/techlit/pdf/PackedLit/69-2060EFS.pdf this should be the instructions for that t stat. best to just look at which color came off what letter and replace back on that letter. you dont know if the last guy wired it right

Hi,
maybe a blown fuse if it has one... if not then you blew the transformer...
Check on the circuit board in the furnace or air handler for a fuse...
if there isn't one... then you will need to replace the 24v transformer... they blow very easily...

heatman101

HONEYWELL WEBSITE:
Go to honeywell.com
Under red welcome sign
Bottom red highlighted box literature/image search
Type in thermostat model number
Click on arrow to right
Then click on the PDF files owners manual / installation instructions
If you can’t find what you want, the bottom left and bottom of web
Page, they have homeowners assistance and Home products to get the help you need.

rh goes on red, this is what will provide power to the heat

rc is red if you want to power the ac unit