The touch screen on my last thermostat failed and I purchased the 3M Filtrete 7 Day Programmable Thermostat (3M22) from Home Depot for about $40. Before I tell you about my experience with this thermostat, here are a couple of things you should know before buying:
1. There are many options out there. I suggest writing out a schedule to determine how much flexibility you need in your device. You’ll see 3 main options for programmable thermostats: 5-2 days, 5-1-1 days and 7 days. 5-2 day units allow for two programs – one for Monday through Friday and another for the weekend. 5-1-1 units allow for 3 programs – one for Monday through Friday and two separate programs for Saturday and Sunday. A 7 day device allows you to have different programs for every day of the week.
2. Pick a thermostat that is compatible with your system. You’ll see Gas/Oil/Elec options, Millivolt options, single-stage/multi stage options, heat pump options and base board heat options to name a few.
Filtrete 3M22 Thermostat:
- 7 Day Programmable.
- Target temperature, room temperature, time of day and status are displayed simultaneously at all times.
- Runs on 2 AAA and/or HVAC power.
- Temporary temperature override.
- Backlit display.
- Hold function.
The Filtrete 3M22 is a 7 day device. It allows you to independently program every day of the week. It splits each day up into four segments – morning, day, evening and night. The default times for these segments are 6AM, 8AM, 6PM, and 10PM respectively. Assuming you keep the default times the unique operation periods are then: 6AM-8AM, 8AM-6PM, 6PM-10PM and 10PM-6AM. In other words, you can program the device to heat or cool differently during each of these periods. The start times for these periods can be changed in 15 minute intervals.
There are a couple ways to override a running program. Pressing the temp up or temp down buttons while a program is running changes the temp +/-1 degree for each push. “Override” blinks on the display and the unit will maintain the newly inputted temperature until the time of day reaches the next program period. At this point, it will revert to programming. The second way to override the programming is by pushing the hold button. You must first press hold and then select a temperature using temp up and temp down. Hold will blink and the unit will maintain the newly inputted temperature until you push the hold button again.
The Filtrete 3M-22 also has a “Program 2” function which is designed to be a special scenario option. It can be programmed like any other day and is activated and deactivated with a single press of the Prog2 button. I use this feature as a “company is coming over button”. I normally keep my house pretty cold so I’ll activate this program for my friends’ sake. (My program 2 is set so the heat comes on to 70 degrees any time of day.) The manufacturer’s documentation suggests programming this feature as an option for when you are away for extended periods like vacations. (Of course you’d set your temperature much lower using program 2 in this fashion.)
Sometimes a device’s instructions can be a real chore to interpret. Not so in this case. The install guide and operation manual are separate booklets and are easy to understand. Setting the clock and programming only took one try. (Note: there is a 60 second rule during programming. If no button is pressed during 60 seconds the unit saves what you’ve done so far and exits the programming routine).
Any button push will activate the back lighting which is much brighter than I’ve seen on other thermostats (though I use HVAC power which might make it brighter than battery power alone).
Included with device
In the box along with the thermostat are the install / operation guides and a small pack of hardware. (4 screws, 4 drywall anchors, 4 jumpers, 4 spacers, and a nice page of wire label stickers).
Installing the device was no trouble at all. (NOTE: Do not disconnect your old thermostat until you label the wires or it will be very difficult to install the new one. If you have disconnected the wires without labeling them, you’ll have to go to the furnace control board and see how the wires connect there – not an easy task in some situations.)
The 3M-22 is thin (less than an inch) compared to some of the thermostats I’ve owned. The unit comes with 4 spacers which I needed in my installation to get enough clearance for the thermostat wires. This is a small disadvantage because the install isn’t as clean as some may prefer (see pictures). The screw holes to mount the unit are behind removable covers. The bottom removable cover also hides the battery compartment. This is a great feature considering some thermostats require that you remove the whole unit to access the batteries. The top removable cover hides the reset switch, the screw down wire terminal blocks and the jumper connections. (Jumpers must be set according to your particular application).
The removable covers are a great idea but it does take some adjustment to get them to fit tightly onto the unit. (The unit has to be perfectly flush on the spacers and/or the wall to ensure good alignment of the covers).
I used a drill with a Phillips bit to install the device to the wall. Another potential disadvantage is the very small screw set on the wire terminal blocks. I needed a P0 Phillips screw driver (smaller than what most people may have readily available) to tighten the wire terminal blocks. You should definitely tighten these by hand to avoid stripping them.
This thermostat requires two AAA batteries. If your thermostat wire bundle includes power (usually the “c” wire), the device doesn’t technically need the batteries to operate (though the low battery icon will constantly flash). Batteries should be installed anyway because they will serve as backup power to save your programming during an outage. If the unit is disconnected from all power supplies for more than 30 seconds programming will be lost.
- Thermometer calibration – nice if you want the reading to agree with other thermometers in your house.
- Swing feature – determines how much the temperature must change from the target temp. before heating or cooling begins. (Default is 0.5 degrees).
- Lock – Pressing time, filter, set clock, and then home in this sequence locks the thermostat to prevent changes in custom settings.
- Copy feature to easily copy programmed days. (This worked intuitively).
- Change filter indicator.
- Energy saving program available as the default. If you choose not to program yourself you can run this program which looks like this:
6AM – 70 degrees, 8AM – 62 degrees, 6PM – 70 degrees, 10PM – 62 degrees
6AM – 78 degrees, 8AM – 85 degrees, 6PM – 78 degrees, 10PM – 82 degrees
So far I am very pleased with the 3M22. Many thermostats only show the current temperature and then switch to the target temperature as you adjust. The 3M22 shows both temperatures at the same time as well as the time of day. The display is crisp and easy to read and the back light is a nice bright bluish white which I like better than the dull yellow you find on many devices. The operation and programming is simple and straightforward. The device has room for improvement in its physical design. Namely, I would have preferred a better mechanism to snap the removable covers on and off. Otherwise, my hat goes off to 3M.