Honeywell Home C-Wire Adapter for Honeywell home Wi-Fi Thermostats and RedLINK 8000 series thermostats
Condition: New
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Availability:
Only 8 left in stock, order soon!
Arrives
Jun 23 – Jun 28
Features
- For Use With Honeywell Home WiFi Thermostats, RedLINK 8000 series thermostats
- The C-Wire Power Adapter makes Honeywell Home smart thermostats compatible with most homes that dont have a common wire..Product Type :Electronic Component. | Package Dimensions :10.0 " L X10.0 " W X10.0 " H.Country Of Origin :United States
- Quickly and easily power connected thermostats that require a c-wire.
- Use for Wi-Fi, 24v Honeywell Home thermostats when a common wire is needed but not present.
- Easy push terminals and an adhesive mount make installation quick and easy.
- Simple adhesive mount allows you to attach the adapter to the outside of your furnace.
- Product Type: Electronic Component. | Package Dimensions: 10.0 " L X10.0 " W X10.0 " H.
- Country Of Origin: United States
Description
Install a Smart Thermostat Without a C-Wire. The C-Wire provides a path for continuous power to Wi-Fi thermostats, but often homes are missing this common wire. The C-Wire Power Adapter makes Honeywell Home smart thermostats compatible with most homes that don’t have this wire.
Brand: Honeywell
Model Name: THP9045A1098
Product Dimensions: 1.75"D x 3.44"W x 5.63"H
Controller Type: Hand Control
Special Feature: Low Voltage
Controller Type: Hand Control
Additional Features: Low Voltage
Specific Uses For Product: Furnace
Temperature Control Type: Heating
Connectivity Technology: Wi-Fi
Power Source: Electric
Voltage: 24 Volts
Display Type: LCD
Control Type: App Control
Control Method: Touch
Connectivity Protocol: Wi-Fi
Mounting Type: Wall Mount
Backlight: Yes
Number of Batteries: 1 AAA batteries required.
Smart Home Compatibility: Smart Home Compatible
Color: White
Shape: Rectangular
Product Style: Simple
Brand Name: Honeywell
Model Name: THP9045A1098
Included Components: Wire Saver C-Wire Adapter
Model Number: THP9045A1098
Manufacturer Warranty Description: No warranty.
UPC: 085267994828
Global Trade Identification Number: 28
Manufacturer: Resideo
Manufacturer Part Number: THP9045A1098
Item Type Name: C-Wire Adapter
Unit Count: 1.0 Count
Item Dimensions D x W x H: 1.75"D x 3.44"W x 5.63"H
Item Weight: 4.16 ounces
Material Type: Metal, Plastic
Finish Types: Matte
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Jun 23 – Jun 28
Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Top Amazon Reviews
TL,DR: Using this with an Amazon Smart Thermostat and works fine. Though I did have a small moment of panic initially after installing everything and setting up the thermostat itself. As I was admiring my work and watching the thermostat come to life and wake up in its new home, it began “clicking on” and then immediately going blank for several seconds. At first I was thinking this may be part of the set up… until it didn’t click on again and was unresponsive in every way. At this point I just knew for sure I fried something, was going to have to call a technician out, and they were going to tell me I’d have to replace my entire system for thousands of dollars. I grabbed my multimeter and verified I had power coming to the furnace and then checked the small 3 amp fuse at the control board which was blown. I switched that out with one I luckily had on hand and everything came back to life as I threw the breaker back on. That was yesterday afternoon and everything has been working fine ever since. Further things I learned during this process: - What each wire does on a heat pump system (hence the pic with them identified). - This adapter combines the fan and condenser wires to free up a wire to be used as the C-wire - The C-wire is effectively the return for the 24v to the thermostat to complete the circuit (think chassis ground on a car or neutral on a home circuit). - If you have an unused wire on your thermostat cable, you don’t need this. Just hook that unused wire to the C-wire in your furnace (look for the blue wire coming from your outside unit and verify where it goes to the control board in the furnace) because even if you get this, you still gotta find a C wire to connect it to.
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Reviewed in the United States on February 1, 2025 Reviewed in the United States on February 1, 2025 by Brad Braswell
This converter was easy to install and came with easy to follow instructions. No issues getting the Honeywell Wifi thermostat connected to our hvac system. Our home was built in the 70s and naturally lacked the 5th wire to connect a 24v line to the thermostat. I was skeptical when buying this as it seemed too good to be true to get that power wire this easily. No issues! Something I ran into during install that wasn't really covered in the wiring instructions: My furnace is an HE model, the yellow wire was split off the main circuit board on the furnace and it was ran to a float safety switch, then off to the thermostat from that switch. Make sure you wire in this box after the switch not directly off the circuit board. This float prevents the unit from running if it is full of water and not draining.
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Reviewed in the United States on October 6, 2024 by TM1NE
This adapter works exactly as intended—I needed it to provide the C-wire for my Amazon thermostat installation. Ours has been in use since 2022! The instructions were good, and the product met all my needs perfectly! If you need a C-wire to install your smart thermostat, this is a solid choice.
Reviewed in the United States on December 5, 2025 by Rk Magill
Great product; instructions were easy to follow and allowed me to install myself instead of calling an electrician (I’ve got no electrical experience). That said, I do wish there were different mounting options as my furnace had a sort of cloth like interior that made it impossible to mount using the adhesive.
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Reviewed in the United States on July 25, 2023 by Patrick
Don't be fooled by this product's low cost or its marketing that you can install it yourself. We used the compatibility tool on the listing to make sure it would work with our situation, watched several very detailed instructional videos, ready through the manual multiple times, and very CAREFULLY installed this thermostat. It worked fine during the winter when heating, but once it became warmer out and required cooling, the thermostat caused a short and burned through the existing wiring and wasn't cooling at all. I had to pay $1,200 total to replace the wiring that was ruined and get another thermostat installed. The AC guy said these products aren't really set up to handle a unit that only has four wires, even with the C wire adapter that we bought and installed with it, which adds a fifth wire, even though these companies market it as being able to handle such a situation. A total scam!
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Reviewed in the United States on March 16, 2024 by Amy
I didn’t have the ability to change to a five wire this adapter made my Honeywell thermostat work perfectly without any issues including Auto change over heat and cool, never ever causes an issue. Even as an Amazon renewed product. Nothing was wrong with it. I can only assume operator error from the last owner because the directions are so simple, just make sure to FOLLOW THE DIRECTIONS on the thermostat documentation because the wiring connection places are different than a normal hookup R G Y W instructions will tell you to use position K and other connections while using this adapter. So long as you follow the instructions, it works perfectly.
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Reviewed in the United States on September 27, 2023 by D
It's functional and easy to install if you're familiar with wiring schematics. Unfortunately, living in Florida, the humidity will eventually degrade the board inside the unit and it will fail if installed inside the garage(where my furnace is located.) Mine lasted several years before failing. If you're in a pinch and need to quickly wire a "C" or common wire, this will do the job. The better option will be to just go in the attic and run a wire for longevity. Troubleshooting may be problematic without prior electrical knowledge and HVAC techs are not cheap. I spent a few hours with minimal electrical knowledge troubleshooting before confirming the issue was the adapter. YouTube University for the win! 5 Stars for ease of installation 1 Star for durability
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Reviewed in the United States on July 10, 2025 by James
Wasn't too bad to hook up. The directions could have been a little bit better but I managed to get it right. I originally had everything hooked up backwards. Once I seen nothing was working I made a phone call to a AC guy I know and he was able to help me out. Told me I had connected everything backwards. Once I switched the wires around everything was good.
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Reviewed in the United States on April 1, 2024 by Lupe