Some time ago, I posted my dilemma regarding identification of my programmable thermostat for my heat pump. There were some helpful responses, but I still don't know what can I have or how to tell whether it is one-stage, two-stage, or whatever. The heat pump has emergency heat strips, if that helps. Otherwise, here are two pictures of the one that I want to replace. They should be large enough that you can tell the wire colors and such. If you can tell me what I have, I'd very much appreciate it!
That is a single stage condensing unit with heat strips. Whether it is called a single or two stage is mostly semantics -- to me it would be a single stage heat pump/ two stage system. If you are looking to replace that Carrier you have, all you need is a HP stat for a system with aux heat strips. Thermostats for actual two stage condensers are less common and more expensive. Hope that didn't muddy up the waters more. Merry Christmas to you and yours--- Larry
Yeah, it muddied them a little, but that's ok! The thermostat is not a Carrier, although my downstairs unit is a Carrier and has an almost identical thermostat. They're probably private labeled for Carrier.
I was mistaken. The name "TOTALINE" is embossed on the front cover, but I cannot find a model number. There are some digits in several places, but none of them resembles a model number.
Good grief, you're right. It was right there in front of me the whole time. It's a P274-1200.
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?There are three classes of people: those who see. Those who see when they are shown. Those who do not see.? - Leonardo da Vinci
Thanks for pointing that out. Duh.
Now, I still need to know which Honeywell thermostat will be the correct replacement. Or, I'd be glad to buy another one of these, if I knew where to get one at a reasonable price.
They're probably not in the office today, but I'll call Honeywell to see if they can help me cross-reference this unit. I went through the manual for the Honeywell RTH7500D, but I'm having trouble correlating some of the wire names.
Wires on this unit are labeled
O/W2* Y1/W2** R G Y/Y2 W/W1 C
Is Y1/W2** actually Y1, W2, or W2**? How is the terminal designation read?
The designations on the Honeywell unit are labeled
C G Y O/B RC R AUX E L
R appears to be jumpered to RC. AUX for a heat pump is the same as W2 for a conventional unit. E for a heat pump is the same as Y2 for a conventional unit.
So here is where I am with this project. The wire on the left below is the terminal on the existing Totaline thermostat. The terminals on the right are where I think they would connect on the Honeywell. The question marks are the wires that cause me to blow up my heat pump since I don't know where to connect them. It seems that the wire designations on the Totaline unit line up more with the conventional unit designations than with the heat pump ones, which is not unbelievable since the thermostats can be used in both systems.
O/W2* ---> O/B (or does it go to W?) Y1/W2** --> W2/AUX R --------> R or R/RC G --------> G Y/Y2 -----> Y or Y2/E W/W1 -----> O/B (or does it go to W?) C --------> C ??? ------> RC (jumpered to R?)
Thanks for working though this mess with me. I hope you see my dilemma. The customer reviews indicate that the installation of the Honeywell unit is a snap. Certainly the mechanical aspects are, but the electrical connections are challenging, and I'm an electrical guy.
Don't bother with the post above. The more I read, the more I learn. I'll post back in a little while with my remaining dilemma in that I have found answers to some of my questions.
What is wrong with the thermostat you have now? Most thermostats that are DIY replaced were not the cause of whatever problem the system was having. If yours is indeed bad, how soon do you have to have one? I have a new Carrier similar to yours that you can have if you can wait for the USPS. Regardless, any new thermostat should have a description of what each wire terminal is for. Your wire colors, luckily, follow the standard color code. Red is the 24 volt hot, and sometimes has a Rh and Rc terminal that are supposed to be jumpered together. ( h and c mean heat and cool respectively) Yellow goes to the contactor in the outside unit, orange goes to the reversing, aka switchover, valve outside. Green to the blower relay in the air handler. White to the auxillary heat strips, and Blue or Black to common. A lot of universal type thermostats have a "B" terminal as well as a "C" or common. If so, do not use the "B" terminal. That is the most common mistake people, including newbies in the trade, make in hooking one up. Get back asap if you need this Carrier stat. Larry
The present thermostat just sits there and flashes on occasion. Most of the time it works.
I found a very helpful tutorial at
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Now I understand most of the functions.
One thing is still not clear, though. The W wire on my thermostat is for the auxiliary heat strips. Some thermostats have terminals for the auxiliary heating relay (labeled "W2") and for the emergency heating relay (labeled "E"). If I were connecting to such a thermostat, would the W wire connect to W2 on the new thermostat? Would the E terminal remain unconnected?
Save your money. Buy a $20 replacement, and you won't have your system running all the times you don't need it to. It will pay for itself in the first month. Programmable systems waste energy, no matter what anyone says. Unless you are in an institution where things go the same every day, day in, day out. Other than that, the best thermostat is you, and you know when to turn it on and off.
Hi, Is youa 'atat broke? If you get a Honeywell Vision Pro7500 or 8000(I have this one) it'll mee your needs. Accompanying manual will tell you what to do. 8000 has few models like 2 stage cooling/2 stage heating et.
Hmmm, Thermostat operator siting by it. Can't slep. can't go to work. Is that you? All the research Honeywell did, government did, utility companies did is for nothing? How programmable 'stat waste energy? Can you elaborate?
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