Braeburn Thermostat Wiring: O/B, W2-E Jumper and C Wire

1. Which Braeburn models does this cover?

Braeburn Systems publishes a separate installer guide for each thermostat family, and the terminal strip is not the same on all of them. This article is built from four of those guides, opened on braeburnonline.com on 13 November 2026:

• 1030 / 1230 Installer Manual (Economy Series, non-programmable, document 1030-100-01)
• 3020 / 3220 Detailed Installer Guide (Premier Series, non-programmable, document 3020W-100-03)
• 5020 / 5220 Detailed Installer Guide (Premier Series, programmable, document 5020W-100-05)
• 7320 Installer Guide (universal programmable smart Wi-Fi thermostat, document 7320-100-02)

Each guide says the model number is on the back of the thermostat. Check it first, because the number decides how many stages the thermostat can run:

All four guides give the same electrical limits: 24 volt AC control circuits, a maximum load of 1 amp per terminal, and 18 to 30 volts AC when the thermostat is powered from the transformer. The 7320 guide adds a 6 amp maximum for all terminals together. None of these thermostats is for line voltage heating; if your old thermostat has thick wires on L1 and L2, see our line voltage thermostat guide instead.

What this article does not cover: other Braeburn models, including older 1000, 2000 and 5000 series thermostats, the touchscreen models and the BlueLink Wi-Fi models, have their own guides and can differ. The rules below are Braeburn’s rules for the models named above, not rules for every thermostat brand.

2. What do the Braeburn terminals mean?

This table combines the “wiring terminations” tables from the four guides. The model column shows where a terminal exists.

Two points catch people out. First, E and W1 are the same screw on these thermostats, so the guide’s heat pump diagrams that mention “E” mean the W1/E terminal. Second, S1 and S2 are sensor terminals, not system wires: do not park a spare wire there. For what each letter usually means on other brands, see our terminal letter index.

3. How do you wire a Braeburn thermostat to a furnace and air conditioner?

For a conventional system the guides’ typical wiring configurations come down to this table. Each cell is the Braeburn terminal that is used.

The rules behind the table, as the guides state them:

• The Rc-Rh jumper comes out only for dual transformer systems. The guides tell you to remove the factory installed jumper for dual transformer systems and for nothing else. If you have one R wire, it goes on Rh and the jumper stays. Our Rh and Rc page and dual transformer page show how to tell which you have.
• With two transformers, C must come from the cooling transformer. All four guides repeat this.
• A two wire heat only or millivolt system uses Rh and W1. The 1030/1230, 3020/3220 and 5020/5220 guides list 250 to 750 millivolt heating only systems as compatible. With no common wire, the thermostat runs on its two AA batteries. See our 2-wire heat only page for that setup.
• Hydronic zone valves are supported on the non Wi-Fi models. On the Premier models a three wire zone valve uses W1 for “zone valve power open” and V3 for “zone valve power close”, with System Type set to 1HD (heat only) or 11HD (hydronic heat with one stage of cooling). Our boiler and zone valve guide explains two wire and three wire valves.

4. How do you wire a Braeburn thermostat to a heat pump?

Heat pump wiring is where the Braeburn families differ most. This table follows the heat pump columns of the four guides.

O or B: which one, and how do you set it?

Braeburn defines O as the “cool active” reversing valve and B as the “heat active” reversing valve. On the 1030 and 1230 they are two screws, and the manual’s note is short: wire O for a cool active valve or B for a heat active valve, never both. On the Premier and 7320 models there is one O/B screw, and the Reversing Valve installer setting decides how it behaves: REVO (the factory default) makes it active in cooling, REVB makes it active in heating.

Use whichever your old thermostat used. One warning that is not specific to Braeburn: on some other brands’ systems a wire on the old thermostat’s B terminal is the common wire, not a reversing valve wire. Our B terminal page and O/B page explain how to tell before you connect it.

When do you need the W2-to-E jumper?

Most homes with a heat pump and electric backup heat have one wire for that backup heat and no separate emergency heat relay. On the models with separate W2 and E terminals, Braeburn’s note for that case is to install a field supplied jumper between the W2 terminal and the E terminal (labelled W1/E/W3 on the 3220 and 5220, W1/E on the 1230 and 7320, with W2 labelled W2/AUX on the 7320). The 1230 manual spells it out: connect the wire to W2 and run a jumper from W2 to E. “Field supplied” means the jumper is not in the box; a short piece of thermostat wire does the job.

The 3020 and 5020 do not need this jumper, because they have a single W1/E terminal that serves as both auxiliary and emergency heat. The 1030 has no W2 or E at all and supports a heat pump with no auxiliary heat only. For what the two kinds of backup heat do, see aux heat vs emergency heat and our heat pump thermostat wiring guide.

What about a two stage heat pump?

On the 3220, 5220 and 7320, a second compressor stage goes on Y2. With two compressor stages and auxiliary heat, the 3220 and 5220 guides put the auxiliary heat relay on the W1/E/W3 terminal as the third stage of heat, while the 7320 guide puts it on AUX. Both the “2 heat / 2 cool, no auxiliary heat” and the “3 heat / 2 cool” layouts use System Type 32HP.

5. Does a Braeburn thermostat need a C wire?

The 1030/1230, 3020/3220 and 5020/5220 guides all open with the same statement: the thermostat requires 24 volt AC power or two properly installed AA alkaline batteries, and when 24 volt AC power is connected the batteries may be installed as a backup. Every wiring diagram in those guides marks C as an optional connection. So if you have no C wire, these models run on batteries.

C becomes a requirement in three cases:

• Wi-Fi on the 7320. Its guide says a 24 VAC common (C wire) is required if the thermostat is connected to a Wi-Fi network.
• The L terminal. The guides say that if the L terminal is used, the 24 volt AC common must be connected to C.
• Some installer options. On the Premier and 7320 models, compressor power outage protection and the AC power interrupt warning are only available when the common wire is on C.

The 7320 also has a K terminal for Braeburn’s optional Share-a-Wire module, which the guide describes as a way to share a wire on existing installations where a common connection is required. K is for that module only. If you need a C wire for another reason, our C wire page and no C wire guide go through the options.

6. Which switch or setting must match the wiring?

The guides for the Premier and 7320 models state that the thermostat ships configured for a 1 heat / 1 cool conventional system, and the 1030/1230 ships with its switch on CONV. Correct wiring with the wrong setting will not run a heat pump properly, so set these before testing.

The System Type codes on the Premier and 7320 models read as stages of heat, stages of cool and the kind of system:

• 11CONV: 1 heat / 1 cool conventional (the factory default). 22CONV: 2 heat / 2 cool conventional (3220, 5220, 7320).
• 11HP: heat pump with no auxiliary heat. 21HP: heat pump with auxiliary heat on the 3020 and 5020. 22HP: the same system on the 3220, 5220 and 7320.
• 32HP: two compressor stages, with or without auxiliary heat (3220, 5220, 7320).
• 1HD and 11HD: hydronic heat only, and hydronic heat with one stage of cooling (3020/3220 and 5020/5220).

How you open the installer settings depends on the model: on the 1030 and 1230 hold MENU for 5 seconds; on the 7320 touch and hold SYSTEM and CONFIG for 3 seconds; the 3020/3220 and 5020/5220 use a two button hold shown in section 4 of their guides. The guides also note that changing System Type resets a group of the settings after it to their defaults, so set System Type first.

7. Wiring steps

Braeburn marks these guides “for installation by experienced service technicians only”. If you do the work yourself, follow the guide for your model and stop if the wires in your wall do not match any of its diagrams.

1. Turn off power to the heating and cooling equipment. Every guide says to disconnect power before beginning installation.
2. Photograph the old thermostat’s wiring and label each wire with the letter of the terminal it was on. Go by the letters, not the colours; our wire colour guide explains why.
3. Read the model number on the back of the Braeburn thermostat and compare your labelled wires with the model table in section 1. Wires on W2, Y2 or L need a model that has those terminals.
4. Mount the sub-base, then connect the wires using the table in section 3 or section 4.
5. Deal with the jumpers. Leave Rc joined to Rh unless you have two transformers. On a heat pump with W2 and E terminals and no separate emergency heat relay, add the W2-to-E jumper.
6. On a 1030 or 1230, set the CONV / HP and HG / HE switches on the back before attaching the thermostat.
7. Install the two AA alkaline batteries, or connect C, or both.
8. Attach the thermostat, restore power and set System Type and O or B in the installer settings (section 6).
9. Test. Set HEAT and raise the set temperature at least 3 degrees above room temperature; the system should start within a few seconds, though with gas heat the fan may not start right away. Switch to OFF and let it shut down. Set COOL and lower the set temperature at least 3 degrees below room temperature. Then switch the fan to ON and back to AUTO.

Two warnings from the system testing section of the guides: do not select COOL if it is below 50°F (10°C) outside, and do not short across terminals at the gas valve or the equipment control board to test the installation, which the guides say could damage the thermostat and void the warranty.

8. What if it does not work after wiring?

These checks pair a symptom with the rule in the Braeburn guides that most often explains it. They do not replace a technician if the equipment itself has a fault.

To confirm 24 volts at the thermostat, use the test in our multimeter guide. For faults that are not about the Braeburn settings, the thermostat troubleshooting guide works through each output. If you are comparing basic battery thermostats, our Emerson 1F83C-11PR article shows how a different brand handles the same heat pump wires with different rules.

9. Frequently asked questions