Nest Power Connector > L7224 Electronic Aquastat

[Jim_CA]

Hello Team, 

• I have this Honeywell L7224 Electronic Aquastat to control the oil-based burner.
• Based on the manual from Nest Power Connector, I should wire C, R, W/Y from Connector to C, R, W/Y on Aquastat.
• In my case, I can find the R&W to Thermostats, However, this Aquastat do not have C, R, W/Y,    instead it includes something like ZR, L1.. etc.   (Please see the photo)
• The current wire includes ZR, L1, L2, C2, C1  B1(Please see the photo)
  • I noticed that C2 and C1 linked to the circulator.
  • I assume Nest Power Connector C, R, W should link to ZR, L1, L2, B1.
  • But I am not sure what is the mapping here between C, R, W vs ZR, L1, L2, B1.

Anyone can help?

 

[Ryan_G]

HI Jim_CA,

Thanks for reaching out here in the Google Nest Community.

The wiring configuration from the photos doesn't show a regular wiring configuration that is compatible with the Nest Thermostat.

I'd like to further check if you could send us a photo of the current wiring configuration from the old thermostat.

Regards,

Ryan

[Jim_CA]

Hi @Ryan_G , thank you for reply.

• The red mark is the input power wire, split into 4 lines, link to ZR, L1, L2,  B1 on the panel.
• The purple mark,  from C1, C2 on the panel,  output to the circulator.
• The yellow mark, 2 small wires covered by that brown cord,  go into the wall and go up to the living room, link to the thermostat. The old thermostat is the old Honeywell. 
• According to the Nest Power Connector manual, I should remove the 2 small wires in the yellow circle, and link them to the Nest Power wire connector.
• Then from Nest Power Connector,  here are 3 wires (C, R, W). I should link those 3 to the red circle.  But I have 4 wire/red circles ZR, L1, L2, B1.  The issue is that I am not sure which 3 I should use and what is the mapping between (C, R, W) and (ZR, L1, L2, B1)

[Ryan_G]

Hey Jim_CA,

Thanks for the reply and for including the photos and details of what's going on.

As the Nest Thermostat only needed a single wire from the HVAC unit, we'll be needing to select which wire is the perfect one to go to the Rh on the Nest Thermostat. We couldn't verify exactly as the wire labels from the unit is not the usual from other HVAC. We should also try to connect one wire from the red circle to be used as a C wire as this is the reason why the error N260 on the display.

Let me know how it goes by replying to this thread.

Regards,

Ryan

[Jim_CA]

so basically,  you are saying I do not need to map (C, R, W) to (ZR, L1, L2, B1),  I only need to link R to one of (ZR, L1, L2, B1) and leave C & W there?

[Ryan_G]

Hi Jim_CA,

Thanks for the reply and we're sorry for the delay.

It is recommended to have your electrician do the wiring as it is needed to be connected to just C, R and W on Nest Thermostat.

Regards,

Ryan

[Jim_CA]

I agree that it needs to be connected to just C, R and W on Nest Thermostat.

The thing I am not figuring out is that for C, R and W, which one should link to ZR, L1, L2, B1？  

[Ryan_G]

Hey Jim_CA,

Thanks for the reply.

It is best to get in touch with your electrician or HVAC technician for us to further check the system and connect those wires.

Regards,

Ryan

[Ryan_G]

Hey folks,

I just wanted to follow up and see if you're still in need of help. Please let us know as we would be happy to answer any questions you may have. 

Best regards,

Ryan

[Jim_CA]

Thank you for the follow-up.

My question is not solved from this post, I am still need help to figure out the mapping between C, R, W vs ZR, L1, L2, B1.

[MelbaDT]

Hey there, 

As Ryan suggested above, it is best to have a professional take a look at your system. Please contact an HVAC technician or a local pro.

Best, 

Melba

[MelbaDT]

Hey there, 

Checking back in should you have further questions here. Have you reached out already to an HVAC technician?

Best, 

Melba

[MelbaDT]

Hi, 

We haven't heard from you in a while so we'll be locking this thread if there is no update within the day. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the Community.

Best, 

Melba