I have a Bryant high-efficiency, 2-stage forced air gas furnace (Bryant 926TA) that is controlled by a Honeywell RTH9580WF thermostat. When using the (default) "Smart Response Technology" mode that seems to be exhibiting inappropriate behavior during morning warmup ('recovery mode'). First, the thermostat seems to be initiating recovery mode excessively early, for instance starting at 5:30 AM to reach the 70 degree setpoint set for 7:30 AM, with an actual (ambient) temp of 64 degrees (i.e. a 6 degree recovery over 2 hours). In addition to this (apparently) excessively early start of the recovery mode, the furnace seems to be cycling between high and low stage heating (based on the fan sound) throughout recovery (for instance, stage 2 for 15 minutes, followed by stage 1 for 10 minutes, then back to stage 2 for 60 minutes and then stage 1 for 35 minutes; though the particulars vary from day to day).

Outdoor low temps are moderate here (Seattle), typically rarely below 25 degrees (and over the last few weeks rarely below 40 degrees). The furnace is fairly new (about 11 months since installation) and I believe was properly started up and configured per Bryant protocols (I have a copy of the Bryant installation, operation and maintenance manual).

The thermostat is connected to the internet via my wifi network and apparently properly configured:

- Thermostat controls: Heating
- System type: Forced Air
- Forced air heating system type: Gas/oil
- Efficiency of heating system: High Efficiency Forced Air
- Number of heating stages: 2 Stages

Wiring has been checked and confirmed correct by the HVAC technician who installed the furnace and the furnace has been configured for staging to be controlled by the thermostat (per HVAC technician).

I have also tried configuring the thermostat to disable Smart Response Technology, with morning start time programmed for 7:30 AM and set point 70 degrees. In this mode the furnace started in stage 1 heating and remained in stage 1 (with an initial difference in actual and setpoint of 7 degrees) until set point was reached - over 2-1/2 hours later!

The furnace is just under 1 year old and I have an HVAC technician scheduled to come out and check the configuration and operation in the next few days (before the warranty period expires). I'll ask the tech to verify that the erratic cycling under recovery mode (Smart Response Technology) isn't due to a furnace operating system override (or safety override). Will also try to verify that with Smart Response Technology disabled the thermostat is actually controlling the furnace (i.e. heating staging) appropriately. Not sure what else could be looked at to determine/fix the odd behavior. Not sure at this point what else can be looked at.

I have thought about having staging controlled by the furnace rather than the thermostat but am not sure how exactly staging control works under this mode (since the furnace doesn't have any information about actual vs. setpoint temps). Am also not aware of the pros/cons of operating in this mode vs. staging via the thermostat.

Any advice or suggestions very much appreciated!




-Wes