Tried resetting the thermostat. Shows 70 degrees for a second. Then back to 78.5 degrees. When I use the arrow adjust to change settings the number does not change

The Peco TA-170 thermostat is designed to control both heating and cooling, and it appears that it may not allow for separate temperature settings for heating and cooling. However, you can adjust the set point temperature for both heating and cooling modes at the same time by following these steps:

1. Press the "SET" button to enter the programming mode.
2. Use the up and down arrow buttons to adjust the temperature set point. The display will show the current temperature set point for both heating and cooling modes.
3. When you have set the desired temperature, press the "SET" button to save the new set point.

To reset the thermostat to its factory settings, follow these steps:

1. Press and hold the "RESET" button for three seconds.
2. The display will show "RST", indicating that the thermostat is resetting.
3. After a few seconds, the display will go blank and then turn back on, indicating that the reset is complete.

Please keep in mind that resetting the thermostat to its factory settings will erase all programmed settings and return it to its default settings. You will need to reprogram the thermostat to your desired settings after the reset.

Hi,

To operate it manually, you'll need to review the steps in the manual to turn off the automated settings and update the default temperature as well.

Thank you.

Some thermostats have a swing setting that can be adjusted. A swing is the setting when you want the furnace to stop or start from the desired set point. For example, you set your thermostat at 70 and the swing is set at 10 degrees. Then the furnace will turn on 5 degrees below 70 and shut off 5 degrees above 70. Check you thermostats manual if it has this option.

on these thermostats remove the outer ring cover and in the lower right side you will see a slide adjustment. move it i believe left for closer cycles and right for longer cycles. it should be 2* on either side of set point. remember that the fan is not furnace shut off.and turning back and forth will not tell you anything. just set it and see how it works then change it again if you need to

Since it's within 2 degrees of your setting it could be one of two things. Most furnaces run longer (pass your setting) to maintain the setting you made. Which really not a problem. However, your thermostat may need calibrating. To test this theory, place a regular wall thermometer next to your furnace's thermostat and see if the two temps match when the furnace cuts on and then when it cuts off.
If the temps are both the same, the furnace thermostat is fine.

If you're turning it down to 68, because no one will be at home during the day, just set it 2 degrees cooler than 68 degrees. You will then wind up with 68 degrees.

Change Temperature Setting Until the Next Program Period (Temporary Change)
? Press UP Arrow or DOWN Arrow until the screen shows the desired temperature setting.
NOTE: The temporary temperature setting is displayed for about 3 seconds and then the room temperature is displayed.
Temporary appears in the display. The setting cancels when the next program period starts or when
you press RUN PROGRAM.

Change Temperature Setting Indefinitely (Hold)
? Move the System switch to the desired position (Heat or Cool).
? Press HOLD TEMP then UP Arrow or Down Arrow to change your setting if desired. (The display changes from showing the setpoint
temperature to room temperature after approximately three seconds).
? To cancel Hold press RUN PROGRAM.


The downloadable manuals for this t-stat are here, and the addendum, here. Page 17 and 18 detail thermostat operation I have copied above. It has graphic representations of keys that do not copy over very well, so if you have questions about the steps above, you should view the manual in the links provided above.

I hope this helps! Please take a moment to rate my reply - thanks!

Your thermostat should have a hold feature indicated by "hold" on or near the hold button. Once this button is pressed "hold" should be indicated somewhere on the screen. When the hold feature is activated your thermostat should stay at the given set-point indefinitely.
If you would like to use the program feature of your thermostat I need to know the make and model before I can help you.

Actually that thermostat is adjustable for only +/- 1 degree. I would make sure it is located close to a radiator/register, whichever you have, to help close that 8 degree variance. The thing about hot water heat is that even when the boiler shuts down those radiators are still putting off heat, so the temp can still shoot up a few more degrees after the stat has been satisfied. Is the boiler shutting down when the stat hits 71* ? If not then the stat may be bad. Honeywell carries a 5 year replacement warranty on that stat. I use the Honeywell Focus stats in almost all my installations. They are a very dependable thermostat. Feel free to ask anything else that will help solve your problem...Rob

the cooling setting will not go below the heating setting. lower the heating setting so you can lower the cooling

use the mode button till program shows up then adjust temp with arrows and hit set