ℹ
info Honeywell
Status rId
Room ID not set or initialization mode display on startup.
? What Causes This
Thermostat is in initial setup state and Room ID has not been configured.
ⓘ What This Means
Press MODE button and follow the Setup Room ID procedure to configure the five-digit Room ID with High, Medium, and Low values.
Source: page 32 of the official manual
From the manual
This error code appears in:
Honeywell Thermostat Battery