Config and wiring help

[Shellyw]

Hi,

I have an all electric system with AC, a single stage heat pump and a humidistat. I have the following wiring from the original thermostat: RC (red), OB (orange), Y (yellow), G (green), W/E (white), C (blue)

I have tried putting the w/e wire in both the W1 and W2 connections. My heat will not come on unless I activate emergency heating in the App. Is there a setting that needs to be changed or is there a different wiring configuration needed? Thanks.

[CoolingWizard]

@Shellyw , can you do me a favor and check your SETTINGS then, EQUIPMENT, and verify that it’s set up as a heat pump with auxiliary heating? The white wire must be in W2/AUX. 

if you have a moment, also upload the picture you took of your old thermostats wiring back plane, so I can see what the wires were attached to there. 

AC COOLING WIZARD

[maedacortez]

Hi Shellyw,

Thanks for reaching out. I understand that you need help connecting the wires on your Google Nest thermostat. I'm happy to help you with this.

Before I can help you, I'll need to ask a few questions to better understand the situation.

• What type of Nest thermostat do you have?
• What is the make and model of your HVAC system?
• Please send me a picture of your control board wires and a picture of your wire connection on your Google Nest thermostat.

I look forward to hearing from you.

Regards,

Manuel

[Shellyw]

I have the Nest Learning 4th Gen. I have a Bryant PA4Z. The system includes the accessory heater model CPHEATER129A0. I do not know where the hvac control board is.  I do not see how to upload an image to this thread.  Currently the white wire is attached to W2 on the nest.  So maybe it is some setting in the Nest app?

[AxelD]

Hi Shellyw,

Thanks for providing that information; it’s really helpful! If the white wire is connected to the W2 spot, it’s correct. As @CoolingWizard mentioned, please verify that your Nest Learning Thermostat is configured as a Heat Pump. To do this, go to Settings > Equipment.
 

Let’s also try to change the O/B wire orientation; that might do your heating turn on:

1. Open the Home app.
2. Tap your thermostat.
3. At the top right, tap Settings .
4. Select Thermostat.
5. Scroll until you find Heat Pump. It should show which wire configuration is currently selected.
6. If the O option is highlighted, select B.
7. If the B option is highlighted, select O.
8. To make sure the issue is resolved, test your heating and cooling again.

Let me know how it goes.

Regards,

Axel. 

[CoolingWizard]

@Shellyw the Bryant PA4Z is what we call a “packaged” unit sometimes referred to as a RTU.  It is not a heat pump model. The PA4Z series is a starlight cooling model.  The Bryant heat pump packaged units are PH4Z the H denotes Heat Pump. I will assume you have a PH4Z with an electric heat strip kit installed.

The standard control wiring on your PH4Z are:

Rc - Power 24VAC 

Y -  Compressor Relay

W2/AUX - Auxiliary Heat (these are your electrical heat strips)

G - Blower Fan Relay

OB - Heat Pump Reversing Valve Control

C - 24V Power Common

If you have taken the Brant model number on the manufacturer label and it is indeed a PA4Z, this model series is NOT a heat pump. 

AC Cooling Wizard