I am trying initial set up of a Google Nest thermostat (2020 version, refurbished and sold by Amazon itself, not a secondary Amazon vendor) for a heat-only setup. I have a Carlin 4223002A oil burner primary control for a boiler. There is not a dedicated C-wire connection on the unit, just a T1 connection for the White wire and a T2 connection for the Red (RH) wire. With my old thermostat, there was a jumper between RH and RC at the thermostat.
Per the Google Nest Power Connector Pro Installation Guide’s “If no C terminal is present in the HVAC system” page/schematic, I have a Honeywell 24V Transformer (https://www.homedepot.com/p/Honeywell-Home-24-Volt-Transformer-AT72D/202264717) connected to a Google Nest Power Connector (NPC), the thermostat wires connected to the NPC, and the NPC connected to the Carlin unit’s T1 and T2 connections.
I am using the Google Home app for the initial Nest setup. The Nest was initially getting a No Power Error 298 and would not allow wifi connectivity nor initial setup. Once I removed the NPC’s jumper (per the Google Nest Power Connector Pro Installation Guide’s “If no C terminal is present in the HVAC system” page), the Nest was then able to connect to wifi and do a system update. The Nest recognizes my RH and W wire connections but it is still getting E298 even though Wifi connectivity remains.
I tried a factory reset of the Nest and then repeated the setup steps, but I am getting the same results...
Any suggestions?
