Thank you! Our HVAC guy wanted $500 to do this job. After watching this video I spent $40 and 30 minutes of my time and it is done. Also, in case someone else encounters this, mine had a white and red wire. Turns out the red one in my case was the same as the black in this video.
I watched this video before installing mine on a ~40 year old furnace with Honeywell control unit, and Honeywell Mercury thermostat. When I removed the ancient 2-wire Thermostat, the Terminals were labeled W and R. So verifying they kept the same nomenclature, even if they don't give instructions for old 2-wire systems. This further backs the instructions here. Works great now.
Thank you so much for this video. My thermostat went bad last night and it was freezing. Went to Lowes this morning hooked up everything and it took off! I'm one happy and warm lady! 🙏
Thank goodness for people that take the time to do these videos. Just to add if you have a red and green wire like me, put the green wire in the w slot. Thank You again John for posting.
THANK YOU for making this video! i was completely unsure of what kind of replacement to get or how to install it since it only had the 2 wires. and the hardware store here doesnt carry the old style. we were cold, and now we are not. THANK YOU! while i do not recommend it, it was 20 degrees Fahrenheit outside and 55 inside, i jumped the 2 wires with the handle from a binder clip with a rubberband around the middle for me to hold. this essentially did what the thermostat would do and closed the connection, telling the furnace to turn on. i did not leave it unattended. and it got the house back up to 70 until i could get the new one installed. it was only like that for a couple of hours. but it did the job. as i said... i DO NOT recommend anyone do this. it could start a fire if the resistance of the wire used creates too much heat. after i got the new wall plate installed i realized i didnt have a teensy tiny itty bitty screwdriver to connect the wires. at that point i remembered i had my multimeter test leads and so used that to jump them until i could acquire the proper tool. besides the tool issue, and the screws they included not being very good (i had trouble getting them into the drywall, should have drilled pilot holes to begin with), thanks to this video, it was a piece of cake.
Thanks John. The manual might as well have been written in hieroglyphics, they made no attempt to help the 2 wire guy whatsoever. You DA man!!! Subbed and liked.
Thanks for help. So simple, but yet so confusing. My old one in old home I bought was wired backwards with phone line, but somehow worked for last 30 years. I went to hardware store and got proper color coded wire. Forget getting any help from Honeywell, I was on their assist line waiting for 1.5 hours till they finally disconnected me. It is amazing Honeywell can stay in business when they cannot write simple easy instructions or be able to have a functional consumer help line. I guess they want you to hire their repair guys to charge the sky for a 15 minute install.
Thank you so much for this video. Honeywell does a lousy job in their instructions as you stated by not showing a simple two wire install. You explained it well and did a wonderful job thank you again may God bless you
This was perfect. I was having trouble doing the identical upgrade and it turns out the original installer had the white and black reversed. There was also a Y stamp next to the black to further confuse me. Seeing where your wires were was exactly what I needed. The instructions provided with the RTH2300B are quite vague. Great descriptive video. Much appreciated
Thank you John!! Could not have done this without your video. Used the same model and installation only took a few minutes. I now have heat again! The old analog one died last night and I've been freezing all night, but thanks to you it is all good now.
Great video. I'm replacing a very old Iron Fireman thermostat with a Honeywell unit similar to the one in the video. My Honeywell unit is non-programmable but that shouldn't make a difference. My problem is that the two wires on the Iron Fireman unit are labelled Common and Day. I don't know how to interpret those wires and where each should go on the Honeywell unit. I've searched and searched but found no reference to the Iron Fireman wire nomenclature. Thanks.
Hey John... nice, simple, clear video. These are the kinds of things that make UA-cam so valuable for so many of us. Thank you for taking the time to post this. Since repairs are so expensive, I often simply experiment with things I don’t know. Since I don’t know how to figure out which wire is constant hot, will I ruin the thermostat by having the two wires transposed, or will it simply not work?
NICELY done - clear concise instructions using words the average home 'Fixer' understands.... thanks for that - instantly understood where I went wrong hooking it back up. TIGHT!
Thank you, thank you, thank you. Even though we installed a different Honeywell model, this was exactly what we needed to connect the two wires (the instruction manual was not helpful).
Thanks John. Found it useful. We are replacing the old manual Honeywell Round thermostat with a Honeywell RTH221B1021/E1 RTH221B1021/A 1 Week Programmable Thermostat. With the old thermostat cover off I only see a white and a pink (faded red?) wire screwed to the base plate contacts so I have to assume it is a 2-wire system (Oil fired, Hot Air, Heat Only). My wife is tired after several heating seasons of changing the temperature settings 2-4 times daily manually, She went to bed early one night and forgot to turn down the heat. We got so warm we ended up getting up at 2AM to turn it back down, It would be great just to set it once and let it run!
Although I'm buying a non programming one different model sorta like the one I have except 40 or so years newer this helps alot. The heater is so old that parts are nearly impossible to find. My uncle had to add wiring to the existing wires as they broke which works although a pain to refix for me but I'm sure it's the thermostat now thats not causing it to kick on. It clicks then nothing but at least the pilot light and blower is still good. The thing is so loose on the wall from usage even if that's not the issue it's one new part and I cant afford 5000 or more to replace the entire unit . Thanks for this video I will try it as soon as I get the part. I'm freezing and my electric heater melted to my extension cord the other day. 😫
Nice job! I got 2 of these from a Home Energy Survey, Opened it up, and thought, oh well, my system is just too old for this. Then I found this video. Now I'm up and running. You've done a great job here, very thorough. Honeywell should be paying you for this. Wonder how many have thrown these thermostats into the trash or returned them because there were NO Instructions. Great work.
thanks man that helped a lot,i'm using it on a oil furnace in the shop,i'm bad to leave it on at night time maybe you and the thermostat will fix 2 problems
Thank you so much for making this video, I have the exact same old mercury thermostat and purchased almost the identical new Honeywell controller, and the 5-wire instructions had me flummoxed thinking I'd have to return it. Nope! This video was just what I needed to hook everything up properly!
Usually you can look at the wires as they are connected to the thermostat you are replacing to see which is which as it should be labeled where it connects.
Since this is an older video I'm not sure if you will see this...or perhaps another view may respond. Our thermostat is a heat only, forced air system. It doesn't have a switch to turn the fan on. Since we don't have central air it would be a pain in the butt to install AC units in our windows as they are the large side-slide windows, not a double hung. My thought is I would like to turn on the blower fan in the furnace to draw in the cool air in the basement and circulate that cooler air up to the main level in an attempt to cool it off a bit during summer. You mentioned at 6:35 you don't have a fan wire hooked up so that switch is not used. Does that mean I would have to rewire just to turn the fan on?
Hope fully yours will work as described , if not good luck with their off shore help desk .as they read the same manual that came with it , I was told by their so-called help desk buy another one .
Hi John. I followed the instructions, checked the wires several times, but our furnace won't start. I set the temperature extra high to drigger it, just to make sure it works. Nothing.
Awesome! What took me a few hours to try to complete before I found your video took me a few minutes to complete after watching your video. Thank you! :)
It really shouldn't matter which wire is which. This is simply open/close of a switch. My two wire system has two brown wires. I traced it back to the furnace, it connects to two terminals labeled "T" and "T". So even the furnace doesn't differentiate.
Thanks. Wonder why Honeywell did not include instructions for people like us who still have the 2wire thermostat. Called their 1800 number but it’s taking forever to get connected to an available install support. Faster to Google and found this video.
Thanks John! Pay attention Honeywell and learn what an instructional video looks like! And while you are at it, Honeywell, read the comments and questions to truly appreciate your customers' frustrations.
This video was helpful. I just purchased a similar thermostat. I did not take the bridge out of the R & RC terminals. Will this impact the function? I connected my red wire to the R.
I am trying to replace an old Lux thermostat with two wires (red & white), that is used for a gas only fireplace. Can I use the Honeywell RTH6500WF thermostat to remotely control my thermostat? I assume the red wire is constant? Thanks for your help!
Red is often the constant hot. Probably most often. That corresponds to the "R" designation for that wire. R = red for my two-wire, gas heat only system.
I have a natural gas wall heater. I have 2 wires coming out of wall going to thermostat (r w) My question is when I install a new thermostat, do I select gas or electric on the switch on the thermostat ? Thanx
I have a white wire on W and a red on RH like you said but then I have a small red wire that goes from RC to RH (looks like the letter C) I don't have air conditioning. Whats this for should I put it back like that on the new one?
Hey man i love the video, i am currently having an issue with the first part which is figuring out where to put these wires. So instead of a black wire i have a blue and white wire, should i still put it in the R slot?
Question, my daughter moved into a condo that has a Honeywell like this thermostat to control the water based radiator heat around the condo. As you mentioned, it seems to have a mind of its own, and probably 30 years old, but its a red/white wire setup. Can she just use this without having to shut anything off, because the building is heated by the condo boilers, not one in each unit. Im used to forced air furnaces, so shes just needs a new thermostat for off or on. Or are special thermostats needed for this sort of heat source
I have the same setting only difference is I have a red wire that is not in use. White wire is in W and black wire is in R and a bridge in between R and RW. My question is if I would like to install a Google thermostat or honeywell wifi thermostat, would I have enough wire to do so ? I saw their installation guide show 5 or 7 wires. I have 3 wires only but I only use the thermostat for heat.
Hi can I just connect the two wires together to test if there is current? my furnace suddenly wont start and I want to test if its the because of the thermostat
Great video! Our system has water heated with gas but the igniter uses electricity; where do I put the switch and does it matter whether the switch is set to gas or electric?
Thank you! Our HVAC guy wanted $500 to do this job. After watching this video I spent $40 and 30 minutes of my time and it is done. Also, in case someone else encounters this, mine had a white and red wire. Turns out the red one in my case was the same as the black in this video.
The manual doesn't go over 2 wire, so come to youtube. Thank you John! I'll be back to watch more of your videos. To the point and helpful.
You helped me replace one of my thermostats two years ago. I came back to your video today for help replacing the other one. Thank you so much.
Love this!!!!
I watched this video before installing mine on a ~40 year old furnace with Honeywell control unit, and Honeywell Mercury thermostat.
When I removed the ancient 2-wire Thermostat, the Terminals were labeled W and R. So verifying they kept the same nomenclature, even if they don't give instructions for old 2-wire systems.
This further backs the instructions here.
Works great now.
Thank you so much for this video. My thermostat went bad last night and it was freezing. Went to Lowes this morning hooked up everything and it took off! I'm one happy and warm lady! 🙏
Thank goodness for people that take the time to do these videos. Just to add if you have a red and green wire like me, put the green wire in the w slot. Thank You again John for posting.
THANK YOU for making this video!
i was completely unsure of what kind of replacement to get or how to install it since it only had the 2 wires. and the hardware store here doesnt carry the old style. we were cold, and now we are not.
THANK YOU!
while i do not recommend it, it was 20 degrees Fahrenheit outside and 55 inside, i jumped the 2 wires with the handle from a binder clip with a rubberband around the middle for me to hold. this essentially did what the thermostat would do and closed the connection, telling the furnace to turn on. i did not leave it unattended. and it got the house back up to 70 until i could get the new one installed. it was only like that for a couple of hours. but it did the job. as i said... i DO NOT recommend anyone do this. it could start a fire if the resistance of the wire used creates too much heat. after i got the new wall plate installed i realized i didnt have a teensy tiny itty bitty screwdriver to connect the wires. at that point i remembered i had my multimeter test leads and so used that to jump them until i could acquire the proper tool.
besides the tool issue, and the screws they included not being very good (i had trouble getting them into the drywall, should have drilled pilot holes to begin with), thanks to this video, it was a piece of cake.
Thank you!!!!! I can’t believe Honeywell didn’t show how to hook up a system with only two wires. Your video helped.
Thanks John. The manual might as well have been written in hieroglyphics, they made no attempt to help the 2 wire guy whatsoever. You DA man!!! Subbed and liked.
Thank you! After watching your detail instructions, I have more confidence in installing the thermostat by myself.
Thanks for help. So simple, but yet so confusing. My old one in old home I bought was wired backwards with phone line, but somehow worked for last 30 years. I went to hardware store and got proper color coded wire. Forget getting any help from Honeywell, I was on their assist line waiting for 1.5 hours till they finally disconnected me. It is amazing Honeywell can stay in business when they cannot write simple easy instructions or be able to have a functional consumer
help line. I guess they want you to hire their repair guys to charge the sky for a 15 minute install.
Thank you so much for this video. Honeywell does a lousy job in their instructions as you stated by not showing a simple two wire install. You explained it well and did a wonderful job thank you again may God bless you
I had given up on my thermostat until watching this. Thank you thank you?
John you are the man I will never get this done without your help you save me a lot!!!!
Thank you so much, John. I just wired mine successfully after handyman couldn't figure it out. Very helpful video!
Thank you. I was confused when I only saw 4 wire instructions. I also have a white and black wire in the garage, this was exactly what I needed.
how long do the batteries last? thanks
The very useful video that helped me replace our 2 wire White Rodgers thermostat with honeywell home non-programmable thermostat. Thank you for this.
Many thanks! Saved me a bunch of stress. Watched your video a few times, bought a similar unit and installed it in 2 minutes!
Thanks so much, John! The instructions booklet was useless, and you saved me hours!
Ditto. This got me up and running on my 2 wire boiler system. Thank you!!!!
This was perfect. I was having trouble doing the identical upgrade and it turns out the original installer had the white and black reversed. There was also a Y stamp next to the black to further confuse me. Seeing where your wires were was exactly what I needed. The instructions provided with the RTH2300B are quite vague. Great descriptive video. Much appreciated
Thank you John!! Could not have done this without your video. Used the same model and installation only took a few minutes. I now have heat again! The old analog one died last night and I've been freezing all night, but thanks to you it is all good now.
Great video. I'm replacing a very old Iron Fireman thermostat with a Honeywell unit similar to the one in the video. My Honeywell unit is non-programmable but that shouldn't make a difference. My problem is that the two wires on the Iron Fireman unit are labelled Common and Day. I don't know how to interpret those wires and where each should go on the Honeywell unit. I've searched and searched but found no reference to the Iron Fireman wire nomenclature. Thanks.
Hey John... nice, simple, clear video. These are the kinds of things that make UA-cam so valuable for so many of us. Thank you for taking the time to post this. Since repairs are so expensive, I often simply experiment with things I don’t know. Since I don’t know how to figure out which wire is constant hot, will I ruin the thermostat by having the two wires transposed, or will it simply not work?
Thanks for the video. My old thermostat didn't want to work anymore. Installed new one and it worked. Very easy steps. Thank you.
NICELY done - clear concise instructions using words the average home 'Fixer' understands.... thanks for that - instantly understood where I went wrong hooking it back up. TIGHT!
Thank you, thank you, thank you. Even though we installed a different Honeywell model, this was exactly what we needed to connect the two wires (the instruction manual was not helpful).
Thanks John. Found it useful. We are replacing the old manual Honeywell Round thermostat with a Honeywell RTH221B1021/E1 RTH221B1021/A 1 Week Programmable Thermostat. With the old thermostat cover off I only see a white and a pink (faded red?) wire screwed to the base plate contacts so I have to assume it is a 2-wire system (Oil fired, Hot Air, Heat Only).
My wife is tired after several heating seasons of changing the temperature settings 2-4 times daily manually, She went to bed early one night and forgot to turn down the heat. We got so warm we ended up getting up at 2AM to turn it back down, It would be great just to set it once and let it run!
Although I'm buying a non programming one different model sorta like the one I have except 40 or so years newer this helps alot. The heater is so old that parts are nearly impossible to find. My uncle had to add wiring to the existing wires as they broke which works although a pain to refix for me but I'm sure it's the thermostat now thats not causing it to kick on. It clicks then nothing but at least the pilot light and blower is still good. The thing is so loose on the wall from usage even if that's not the issue it's one new part and I cant afford 5000 or more to replace the entire unit . Thanks for this video I will try it as soon as I get the part. I'm freezing and my electric heater melted to my extension cord the other day. 😫
Nice job! I got 2 of these from a Home Energy Survey, Opened it up, and thought, oh well, my system is just too old for this. Then I found this video. Now I'm up and running. You've done a great job here, very thorough. Honeywell should be paying you for this. Wonder how many have thrown these thermostats into the trash or returned them because there were NO Instructions. Great work.
Brett Penza thank you so much for the beautiful comment
Thanks. No one else showed what to do with only two wires.
thanks man that helped a lot,i'm using it on a oil furnace in the shop,i'm bad to leave it on at night time maybe you and the thermostat will fix 2 problems
Thank you so much for making this video, I have the exact same old mercury thermostat and purchased almost the identical new Honeywell controller, and the 5-wire instructions had me flummoxed thinking I'd have to return it. Nope! This video was just what I needed to hook everything up properly!
Thanks for this video. I hate calling companies to get help. On the phone for hrs. This really helped me out
Stv45 The guy thanks for watching and for the kind words
I was about to return my new thermostat until I saw this video. Thank you for posting this, you're a lifesaver
Meeee toooooo
John that was super helpful. I could not get this T-stat functioning without your video.. Cheers,
Thanks man, just what I needed with my non programmable Honeywell thermostat. They really need to update their documentation.
Excellent. I have a 2 wire setup that I'm looking to change. My wires are red and grey. I'm saving this video for later.
Thanks, this was just what I needed, Honeywell should pay ya for this instructional video! Lol. Cheers
Thank you so much John. Saved me a bunch of time. My mom is happy too!😁
Happy to help. Thank you for watching
Thank you! I have an older home with only a black and white! You saved me!
I just happened to have the identical digital thermostat, thank you so much for posting this!
how long does the batteries last? thabks
Thank you John! That was super helpful in replacing our old two wire thermostat! First time doing any home electrical work and it worked! Yay!
Usually you can look at the wires as they are connected to the thermostat you are replacing to see which is which as it should be labeled where it connects.
You are freaking awesome!! I looked everywhere and nobody has this!! Well done sir
Eddie Duque TVs thank you so much. So happy my videos are able to help others
Thank you sooo much! You did such a great job explaining this. Way better than the “instructions”. Awesome!!
Excellent, thanks for the information - was needed as like you said 2 wire is not in the manual.
Thank you so much!
Great explanation!
I was able to follow and install thermostat myself!🎉
Since this is an older video I'm not sure if you will see this...or perhaps another view may respond. Our thermostat is a heat only, forced air system. It doesn't have a switch to turn the fan on. Since we don't have central air it would be a pain in the butt to install AC units in our windows as they are the large side-slide windows, not a double hung. My thought is I would like to turn on the blower fan in the furnace to draw in the cool air in the basement and circulate that cooler air up to the main level in an attempt to cool it off a bit during summer. You mentioned at 6:35 you don't have a fan wire hooked up so that switch is not used. Does that mean I would have to rewire just to turn the fan on?
Thanks for the great video, going to try to install it today for our oil furnace
Did it work? I also have oil no ac. But my wires are black and blue!
Thanks John! Helped me out a lot. Got my mum setup with the new digital meter and she’s happy now. Great video thank you for sharing it
how long do the batteries last?
Thank you so much bro, real simple the way you explained it , was going crazy with the other videos ! God bless you brother !
OMG... John!!!! Thank you so very much. You are awesome!!
thank you for the clear instructional video. :-) I was able to do mine by watching this.
Hope fully yours will work as described , if not good luck with their off shore help desk .as they read the same manual that came with it , I was told by their so-called help desk buy another one .
Honeywell,WTF were you thinking by not including 2 - wire hookup instructions?
Waterheat control does it work the same
your awesome. thought i lost 300 bucks when i bought mine till you explained 2 wire set up great videos keep it up
Dave Hoten thanks for watching and for the kind words
Thanks , I just installed the same thermostat with 2 wires.
Hi John. I followed the instructions, checked the wires several times, but our furnace won't start. I set the temperature extra high to drigger it, just to make sure it works. Nothing.
Awesome! What took me a few hours to try to complete before I found your video took me a few minutes to complete after watching your video. Thank you! :)
John thanks great job, why couldn't Honeywell have made it this simple!
It really shouldn't matter which wire is which. This is simply open/close of a switch. My two wire system has two brown wires. I traced it back to the furnace, it connects to two terminals labeled "T" and "T". So even the furnace doesn't differentiate.
Peter Scott this is a very good point!
Thank you--very helpful. My system has a red and a yellow wire. New thermostat working great.
Thank you for this video!!! Exactly what i needed.
Thanks. Wonder why Honeywell did not include instructions for people like us who still have the 2wire thermostat. Called their 1800 number but it’s taking forever to get connected to an available install support. Faster to Google and found this video.
Thank you! You just saved me a ton.
Thanks John! Pay attention Honeywell and learn what an instructional video looks like! And while you are at it, Honeywell, read the comments and questions to truly appreciate your customers' frustrations.
This video was helpful. I just purchased a similar thermostat. I did not take the bridge out of the R & RC terminals. Will this impact the function? I connected my red wire to the R.
Thank you ! You explained everythings so well and I was able to replace the old mercury thermostat myself 😀👍🏻
Thanks! I needed this exact info!
Omg finally somebody who has the same setup i have and explained it perfect, thank you partner you made my day.
Thank you so much for the kind words
@@DIYManiacJohnP Same compliment Sir. Thank you.
John, i have the same setup, but both wire is withe, the black wire should be POSITIVE, right
Our old thermostat and even the new one the thermostat isn't controlling the temp. Its heating even when the thermostat is on off.
I had the same old thermostat as you. Red was constant black was variable 😂
Thanx a lot. Just installed one today with the exact same new one.
Thank you so much for this video John! You saved me hours of my time (and potentially my marriage! 😂)
My two wires are brown what happens if you put the wires in the opposite places
I am trying to replace an old Lux thermostat with two wires (red & white), that is used for a gas only fireplace. Can I use the Honeywell RTH6500WF thermostat to remotely control my thermostat? I assume the red wire is constant? Thanks for your help!
How do you hook up the blower fan so it runs separately without the heat on?
Red is often the constant hot. Probably most often. That corresponds to the "R" designation for that wire. R = red for my two-wire, gas heat only system.
I have a natural gas wall heater.
I have 2 wires coming out of wall going to thermostat (r w) My question is when I install a new thermostat, do I select gas or electric on the switch on the thermostat ? Thanx
Hello thank you for the help video is very good the question if you do not know the color of the wiring how you figure out which one which thank you
Perfect for what I needed! Thanks!
Thank you , solved my two wire quandary
Thank you!
Hello,
That's a great video, great!! But how to adjust the time in 24 hour format ???
If I have heat & cold AC unit with the 2 wires do I leave the bridge pin on the R & RC?
yes
thanxs for showing us how to check what wire is hot
Thanks for the great video. Any idea if this product would work for a gas fireplace ? Thanks
I have a white wire on W and a red on RH like you said but then I have a small red wire that goes from RC to RH (looks like the letter C) I don't have air conditioning. Whats this for should I put it back like that on the new one?
Thank you, simply and easy instructions
good looking out brother keep up the good work
Hey man i love the video, i am currently having an issue with the first part which is figuring out where to put these wires. So instead of a black wire i have a blue and white wire, should i still put it in the R slot?
Question, my daughter moved into a condo that has a Honeywell like this thermostat to control the water based radiator heat around the condo. As you mentioned, it seems to have a mind of its own, and probably 30 years old, but its a red/white wire setup. Can she just use this without having to shut anything off, because the building is heated by the condo boilers, not one in each unit. Im used to forced air furnaces, so shes just needs a new thermostat for off or on. Or are special thermostats needed for this sort of heat source
I am sorry but i can’t guide you on this as there are many factors involved. You will need to speak with a certified installer
I have the same setting only difference is I have a red wire that is not in use. White wire is in W and black wire is in R and a bridge in between R and RW. My question is if I would like to install a Google thermostat or honeywell wifi thermostat, would I have enough wire to do so ? I saw their installation guide show 5 or 7 wires. I have 3 wires only but I only use the thermostat for heat.
Hi can I just connect the two wires together to test if there is current? my furnace suddenly wont start and I want to test if its the because of the thermostat
Yes this will have the same effect and it will close the loop and turn the furnace on
Great video super helpful. Well done. Thank you!
Very informative, thank you for the instructions!
Nice clear video.
When using two wires, can it be programmed for different times?
Thank you
Great video! Our system has water heated with gas but the igniter uses electricity; where do I put the switch and does it matter whether the switch is set to gas or electric?
if you buy a smart thermostat with wifi is it the same. I only have heat in my cabin. would be nice to control from a distance. thanks for the video.