The short answer
A Google Nest works on most Bryant systems in Northern Virginia. A regular Bryant gas furnace, air conditioner or heat pump, the Legacy and Preferred lines, runs on a Nest once a C wire gives it steady power. Bryant Evolution is the exception. Its Evolution Connex control talks to the equipment over four wires Bryant calls the ABCD bus, and Bryant says the Connex replaces the conventional thermostat. A Nest can’t use those wires, and Google says proprietary systems aren’t compatible with a Nest. Keep the Evolution control on an Evolution system. On everything else, a Nest, an ecobee or a Honeywell Home all work.
Evolution or regular: how to tell
Start at the wall. If the thermostat says Evolution, you have an Evolution system. If it doesn’t, turn the system off, pull the thermostat off its plate and look at the terminals. Take a photo before you unhook anything.
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| What you find | What it means |
|---|---|
| Four wires on terminals marked A, B, C and D | Bryant Evolution. Keep the Evolution control |
| Letters like R, C, W, Y, G and O | A regular 24 volt Bryant. A Nest works with a C wire |
| Letters, but no C and no spare wire in the bundle | A regular Bryant that will run a Nest short on power. Plan on a C wire |
| The furnace or outdoor label says Evolution | Evolution equipment. It’s usually wired for the Evolution control, so check the wall |
Bryant is built by the same company as Carrier, and Evolution is wired the same way as Carrier Infinity: two of the four wires carry power and two carry data between the control and the equipment. Bryant’s product sheet lists the Evolution Connex as compatible with Evolution indoor equipment only, so it’s no use on a regular Bryant either.
Nest on a regular Bryant: the good and the catch
The good: a Nest Learning Thermostat learns your schedule, shows your heating and cooling hours, and on a heat pump its Heat Pump Balance setting decides how much to lean on the backup heat. If your house runs on Google Home, it’s the easy fit.
The catch is power. Plenty of Bryant furnaces in older Northern Virginia houses were wired with no C wire, because the old thermostat didn’t need one. A Nest does. Without it, the Nest borrows power through the heat and cool wires, and these are the signs Google lists:
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| What you notice | What’s going on | What fixes it |
|---|---|---|
| A low battery warning, a dark screen, or Wi-Fi dropping | Not enough power without a C wire | Connect a spare wire as C at both ends |
| Delayed or Starts in, again and again | The Nest is waiting on power before it runs the system | The same C wire. Once it has power, the waits stop |
| Clicking, the system cycling on its own, or the fan running nonstop | The Nest is pulling power through the heat or cool wire | A C wire, then set the fan to Auto |
| E1, E297, N260 or N261 | Google’s codes for a missing or weak C wire | A spare wire, Google’s Nest Power Connector, or a new wire pulled |
Nest codes on a Bryant, and what’s usually behind them
The Nest code tells you which wire lost power. The rest are in our Nest error code guide.
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| Nest code | Google says | On a Bryant, usually |
|---|---|---|
| E2, E22, E72 | No power wires, Rc or Rh required | Power is off at the furnace or air handler, or the R wire came loose |
| E4, E24, E74 | No power to Rh | The furnace switch or breaker is off, the blower door isn’t seated, the board’s fuse blew, or the condensate float switch tripped |
| E5, E25, E75 | No heating or cooling detected | W1 or Y1 isn’t connected, or a wire broke in the wall |
| E9, E29, E79 | No power to C | The C wire isn’t landed at the furnace board, or it broke in the wall |
| E52 to E58 | Overcurrent on HVAC equipment | A shorted wire or a failing part. Stop resetting it. More in the Nest overcurrent error |
Before you reset anything, look at the furnace. A Bryant furnace blinks its status code on the control board, usually where you can see it through a small window on the lower door. Write the pattern down first, because cutting the power can clear it. Our Bryant furnace codes guide reads them, and how to reset a Bryant furnace covers the reset done right.
Heat pump trouble that comes from the setup
- Heat blows cold and the AC blows warm. The reversing valve setting is backwards. Bryant’s service manual has the thermostat power O on a call for cooling, and a Nest starts on O, so on a Bryant check the wire before the setting. The setting is in the Google Home app under Settings, Thermostat, Heat pump.
- Heat strips run all the time, or never. The AUX wire isn’t where the Nest expects it, or Heat Pump Balance is set to save the most on a cold night. See aux heat vs emergency heat.
- Dual fuel. A heat pump with a gas furnace as backup needs a Nest that lists dual fuel. Check Google’s compatibility checker and read dual fuel in Northern Virginia.
Nest vs Evolution vs Honeywell vs ecobee on a Bryant
Is Google Nest the best thermostat? On a Bryant, it depends on which Bryant.
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| Thermostat | Runs Evolution? | Runs a regular Bryant? | Pick it if |
|---|---|---|---|
| Google Nest Learning Thermostat | No | Yes, with a C wire | You want it to learn your schedule and you use Google Home |
| Bryant Evolution Connex | Yes, it’s built for it | No. Bryant lists it for Evolution indoor equipment only | You have Evolution equipment |
| Honeywell Home smart thermostat | No | Yes | You want room sensors or lots of models to pick from |
| ecobee | No | Yes, with a C wire or its power adapter | You want room sensors and Alexa or Apple Home. We install it for a flat price |
Our pick by system
- Bryant Evolution: keep the Evolution control. If the control itself is failing, replace it with another Evolution control, not a Nest.
- A regular Bryant furnace and AC: a Nest if you use Google Home, an ecobee or Honeywell Home if you want a sensor in the bedroom that runs cold. Have a C wire run either way.
- A Bryant heat pump: a Nest Learning Thermostat or an ecobee, with the backup heat on AUX and the reversing valve checked on the first cold night.
When to call us
Call when the Nest code keeps coming back, when the furnace light is blinking, or when the house won’t hold temperature. We work on Bryant furnaces, ACs, heat pumps and Evolution systems across Northern Virginia, and we check the furnace code and the thermostat wiring on the same visit. A repair visit starts with a flat $99 diagnostic, and you get the price of the fix before we start. Heat pump acting up? See heat pump repair.
Want the smart thermostat done for you? Our ecobee install is a flat $549 for the thermostat and the install: wired, mounted and set up on your phone before we leave. Heading into winter, our heating check is $67 per system, through December 31: furnace, heat pump or boiler.
Have a different brand?
- Google Nest on a Trane system
- Google Nest on a Carrier system
- Google Nest on a Lennox system
- Google Nest on a Rheem or Ruud system
- Google Nest on a Goodman, Amana or Daikin system
The system we put in first
Built to take a beating. Put in by our crew.
Heat lamps, snow and rain on one outdoor unit: that’s Trane’s own film. We’re a Trane Comfort Specialist, on Trane’s own dealer locator, and when you pick a Trane, our crew puts it in.
Films: Trane’s own.
Book it
Rated 5.0 stars across 1,138 reviews on Google, Angi, Yelp, the BBB and Facebook. Virginia Class A license 2705192276. Book a visit online or call (703) 997-9757. Book from goswiftpro.com/cookiesoffer and a box of warm cookies comes with the visit.
Questions people ask
Does Google Nest work with Bryant?
Yes on regular 24 volt Bryant furnaces, air conditioners and heat pumps, the Legacy and Preferred lines, once there’s a C wire. Not on Bryant Evolution, which runs on its own control over the A, B, C and D wires.
Can I replace my Bryant Evolution thermostat with a Nest?
No. Bryant says the Evolution Connex replaces the conventional thermostat and talks to the equipment over the ABCD bus, which a Nest can’t use. Replace a failing one with another Evolution control.
What do the A, B, C and D wires on a Bryant thermostat mean?
They’re Evolution’s ABCD bus. Two carry power and two carry data between the control and the equipment. A regular thermostat, Nest included, has nowhere to put the data wires.
Is Bryant the same as Carrier?
They’re built by the same company. Bryant Evolution is wired the same way as Carrier Infinity, and the thermostat answer is the same: keep the brand’s control on those, use any smart thermostat on the regular lines.
Why does my Nest say no power to Rh on my Bryant furnace?
Usually the furnace switch or breaker is off, the blower door isn’t seated, a fuse on the board blew, or a float switch tripped. If those check out, call a tech.
