[tdcarter]

Had a Daikin modulating system put in last year. Modulating gas and FIT A/C.

Twice I called the contractor back during the summer because the house was getting too warm overnight. It seemed the thermostat was almost randomly off by 4°. They swapped it out both time.

Later I figured out that the lighted display screen and spiffy little LED underbar (to show it's working heating or cooling) were influencing the thermostat.
We calibrated the thermostat during the day, when both features were turned on.

I had the display on continuously as a clock and the underbar was showing the red or blue to let me know it was running. Come bed time I programmed the night dim feature and turned both the display and underbar off.
I'd go to bed at the same time the lights shut off thinking the house would stay at temperature.

So now with less heat being generated by the thermostat itself it would cool down while the house heated up, driving the person constantly setting the thermostat crazy! There was about a 4° temperature in the thermostat reading between display lights being on or off.

Display screen and underbar light are now off!! (The display lights momentarily if I touch the screen or dial to make changes.)

Anyone else notice this?
(The A/C issue was during the summer, all resolved once I turned off the light. Just kind of posting it out here as an FYI and see if anyone knows about it or experienced it.)

I'm trying to do some temperature tracking to see if there is also an issue with the system being over sensitive. Heater is runner forever in the morning but I think it is because the wall is cold and influencing the air around the stat.

 

[Bazooka Joe]

Maybe you got a decent size hole behind the thermostat, from where your old thermostat was where unconditioned air is breathing on your thermostat.

https://www.google.com/url?sa=t&rct...ts/oneplus/pros/DaikinOnePlusProfessionals.pdf&usg=AOvVaw2r4PliOoeOfy4mouZAuA20

Page 13 and page 16 do’s and don’t

 

[tdcarter]

Maybe you got a decent size hole behind the thermostat, from where your old thermostat was where unconditioned air is breathing on your thermostat.

Will give it a look. I did run a new wire when they were installing the heater last January. I know there is blocking right below where the thermostat is located, the old 4' drill bit came to the rescue. But there could be cold coming from the attic down the wall. Will check insulation and verify.

 

[Bazooka Joe]

Will give it a look. I did run a new wire when they were installing the heater last january. I know there is blocking right below where the thermostat is located, the old 4' drill bit came to the rescue. But there could be cold coming from the attic down the wall. Will have to give it a look and check insulation.

Just plug it if it is open like the in the photo ( did not see where they mentioned that in the install guide unless I missed it ) on page 13 of the install guide….

Your suppose to register the thermostat along with the rest of your equipment as Daikin offers the best manufacturers warranty once registered. The thermostat comes with a 12 year warranty once registered with a Daikin system I believe..

California or Quebec need not be registered to receive the manufacturers maximum warranty.