Nine years ago when we moved into our townhouse, I was appalled by the ancient thermostat located in a far, obscure corner of our living room. I hired an HVAC company to install a newer Honeywell programmable model in the main hallway, certainly more convenient. It was still a 1-zone townhouse but now we could properly and less ambigously control our own heat. [That’s an inside joke to my wife.]
This year, I found myself yet again appalled by the 90’s era thermostats in our new 2-zone house. They were digital, but really funky. After debating the Nest model, I ordered a Honeywell 7-day programmable WiFi thermostat from Amazon. They only had one in stock! It was scheduled to arrive on Friday.
Meanwhile, I did some research, and it was possible that I didn’t have the proper wiring. [In case you are not interested, please feel free to skip ahead a paragraph or two.] Thermostats are connected by various wiring to control your furnace and/or AC unit. There are a number of wires labelled “W”, “Y” etc etc. Each one controls specific HVAC features. You can look those up separately. If you don’t have central air, you won’t have those wires to connect. It is important to connect your wires correctly. Regardless of the wire color, if it was connected to “W” on the old thermostat, you better connect it to “W” on the new one.
In the newer thermostats like mine where you will need to power an LCD screen, you need a separate power line supplying 24V going in as well. It is referred to the Common or “C” wire. The old thermostats didn’t need it, so believe me, your home builder did not take the extra effort to future-proof your HVAC needs.
[End of boring technical details.]
I took a quick peek behind one of the existing thermostats, and confirmed there was no Common or “C” wire to provide power. I would need an HVAC guy or an electrician to add an additional power supply wires for both thermostats behind the wall. I called our current HVAC company, but they refused to help me in any way to install new thermostats, unless I bought their overpriced models and paid them to do the entire installation. No thanks. I called an electrician that we have had out for various job estimates. He was able to do the work without requring me to give a pint of blood.
Here’s the slight wrinkle -> Thermostat #1 had not arrived yet, so how would we test? We need another thermostat anyway, right? While the electrician worked, I ran to Home Depot and purchased their one and only model on the shelf. I also ran a few other errands in that hour he needed to run the wiring. Now, the electrician said he could do everything else, but he wouldn’t actually hook up the thermostat itself. However, he wanted to see it, so he asked to hang around watch. Cool guy, bte. We tried out the first thermostat, and success!
When the 2nd (or 1st?) thermostat finally arrived in the mail, I installed that too. I just wish I could converse with it, a la the U.S.S. Enterprise computer.