I have compiled the most useful user reviews about the Honeywell RTH6450D1009 Thermostat from internet. Here you are :
Watch out for “Smart Response Setting”, February 11, 2011 (4 star)
85 of 89 people found the following review helpful
I had to replace an older cheaper Honeywell that decided it didn’t know what time of day it was.
I decided to go with this more expensive model– but I had reservations after having read some reviews and comments elsewhere where some people complained that the furnace was always on, or they were burning more oil or gas than before. . .
I found the reason–
It’s called ‘Smart Response Technology’
It’s ‘ON’ by default if you do the quick DIY install.
To turn it ‘OFF’ you have to download the FULL MANUAL from the Honeywell site to see how to get into the ADVANCED Settings of the device. The pamphlet you get in the package is just your BASIC setup.
I bought the programmable Honeywell to control my oil usage and keep the furnace from heating the house in the dead of the night when everyone is in bed. And I would set the Program to turn the Furnace ON and reset the Temp back to 70 degrees at 7 AM. In short– The Furnace turns ON at 7 o’clock and in time, (20 minutes or so) the house gets warm.
What SMART RESPONSE does is uses an algorithm to attempt to get the house to the Programmed Temp BEFORE the Programmed Time. The result is the Furnace will turn ON an hour or more BEFORE the time you set to raise the temperature until it hits 70 degrees EXACTLY at 7 AM.
Okay– it’s a nice, cute helpsy idea that I’m sure a Honeywell Programmer/Engineer is rightly proud of. Problem is, the Furnace is BURNING OIL when I don’t WANT IT TO.
I didn’t notice what the Thermostat was doing until late one night I was watching a movie real late– when I heard the Furnace go ON and STAY ON at 4:30 in the morning. And I was like: “WTF?” When I went to look at the Thermostat, it displayed: ‘In Recovery Mode’
That was the Smart Response circuit attempting to ease the night-time temp back up to 70 degrees in time for 7 AM. Except that meant the thing was BURNING MY OIL AT 4 IN THE MORNING!! If I hadn’t been awake, I would never have noticed this.
So disable “Smart Response”. That way the Furnace only comes on when YOU program it to.