AC 24 Volt Transformer, C Wire Adapter, Compatible with All Versions of Ring Doorbell and Thermostat for Ecobee,Sensi and Honeywell, 315" Long Cable

This is perfect for older houses! I only had 4 wires behind my old thermostat and knew essentially nothing about wiring a furnace. This is my first time ever changing a thermostat and it was pretty easy. There were a few special tweaks needed for an older house though. I have advice for people using the Amazon Thermostat with this! See below. -First and foremost you can get through this process as safe as possible if you use ChatGPT. Also, follow the normal instructions included when adding the device to the Alexa app. Turn off circuit breakers, etc. It's good to have a live wire tester to make sure it's safe (they're cheap on Amazon) OR just turn off every breaker to be sure there's no power to the wires. -The C wire needs to come from outside the thermostat while all the other wires are inside your wall, so you'll need to cut out a tiny bit of plastic so the C wire can also fit in where it's needed. There is a small door that flips up and down on the device you plug your thermostat into. Carefully rip that door off or you wont be able to close it with the C wire in the way. You'll understand when you get to wiring it. Once that door is removed and you cut out an area for the C wire, then you should be able to attach the actual thermostat with no issues. -The wire can but cut shorter if you like. Splice it correctly again if you do. Remember! ChatGPT can help if you don't know. -Do NOT twist the two C wires together because they go in different slots on the thermostat! KEEP THEM SEPARATE. -One wire goes into the C slot. The other wire will be intertwined with the RH (hot) wire. Works like a charm. 10/10.

Works great. I used it to power a Wired Ring Door Bell. Easy install, just attach the wires and plug it in.

Worked perfectly.

I took a star off because while the instruction may not be wrong but did not work for me. Here is how I get my Amazon Thermostat to work. Here are some facts first- 1. The HVAC does have a C wire but could not power the Amazon Thermostat, it appears that my HVAC C wire has 24 volts but not enough current (amps) to power the Thermostat. Hence need to add the transformer. 2. I live in Florida, so the heating and the AC are in one unit, that means the R(H) and RC are jumped together with only 1 Red wire. 3. I can't say for other areas but in South Florida this way will work. 4. When I followed the transformer instruction and mirror to the Amazon Thermostat, push the right button to connect one transformer wire to RH and the other wire to C and the Red wire from HVAC to R. I only get heat and not AC. 5. To correct the issue and viewed at least DIY videos and learn to fix it. You need to merge the Red wire and one of the transformer power wire to a new leg that can insert into the R with the bottom right blue clip pushed up to allow the R and RC jumper to connect internally. Once that was done, everything work correctly. I have have heat and AC. The reason that I had only heat but not AC, because the R in the Amazon Thermostat is for "HEAT" and since you push the right blue clipper down, it disconnect the R and RC. There for there is no power sent to the AC unit. Since the the Amazon Thermostat cannot easily jump the connectors, then you must introduce a 3rd wire for the R connection with transformer power wire, Red from HVAC, bundle all three wire together. Hope this help you to install without a C wire or low amperage C wire. I have to say the Thermostat works great. Good luck.

Would buy again

I upgraded to an Amazon thermostat but didn't have a C wire. This worked great to power my thermostat. Since my thermostat is over the air return, I dropped power into the return and put an outlet behind the air filter (yes, I used rated cable.) A completely hidden installation. I love it when a plan comes together.

This unit worked well to power a Ring Wired doorbell. It is an easy solution where you dont have wiring running to your doorbell location but have a plug nearby.

Super long cable (315 inches / ~26 feet / 8 meters) — This is the standout feature. You can route it from a distant outlet (garage, basement, or indoor wall) to your outdoor doorbell or upstairs thermostat without needing extensions or worrying about reach. Many shorter adapters (10-16 ft) fall short in real homes; this one gives you flexibility for clean, hidden installs along baseboards or exterior walls. Works seamlessly with all Ring Video Doorbell versions (including Pro, 2, 3/4, Plus), plus smart thermostats like Ecobee, Sensi, Honeywell, Nest (1st/2nd gen), and others needing 24V AC. Output is typically 24V/500mA, which matches or exceeds what these devices require for stable operation—no underpowering issues that cause random reboots or battery drain. If your setup lacks existing doorbell/transformer wiring or a C wire, and you want something affordable, long-reaching, and dead-reliable, grab this. It’s especially great for renters, older homes, or anyone avoiding wall modifications. Saved me from constant recharges and false alerts highly recommend for the price and convenience.

Llegó abierto y al parecer usado...

I’ve been using this 24V transformer to hardwire my Eufy E340 smart doorbell, and it’s been working great so far. Installation was straightforward, especially with the long cable — it gave me plenty of flexibility to route it cleanly without needing extensions. The power output is stable, and my doorbell stays consistently charged without any dropouts or issues. I also like that it’s wall-mountable and compact enough to keep things tidy. It feels solid and reliable, not cheap or flimsy. Overall, it’s a simple but effective solution if you’re looking to avoid constantly recharging your smart doorbell battery. Definitely a worthwhile upgrade for a cleaner, more permanent setup.

Bought the transformer for a Black & Decker Wi-Fi thermostat for my freestanding Napoleon gas fireplace. Has been working great.

Used this on our Roger’s Shaw xfinity doorbell camera as when we moved our house didn’t have a door bell or chime so it was easy to drill a small hole through house and feed this in and plug it in, we use it for the app and camera wasn’t needing a door chime in the house because we get the notifications via app.

Solve all of your wired doorbell woes with this 24V transformer. Something reliable in a shifting and scary world.