They didn’t leave you with a binder of manuals for all the appliance etc?

Is the HVAC system on and running? The 24v power from the system should be powering the thermostat. You could also pull the thermostat off its mounting base and replace its batteries.

Watch out Worthy ... you might be on Candid Camera! ;-)

You sure that is a thermostat and not an alarm panel?

Ask the seller. Call an HVAC tech. Replace it with something you like better or are more familiar with. Lots of options.

Batteries. It’s probably wireless. Just take it off (look for a release tab. Mine is on the top) and put new batteries and see if that wakes it up.

mrs. worthy just found the 45 page (!) instruction and set-up manual.

When life was simpler and round.

I like "Elmer"'s suggestion best! Maybe I can move the Honeywell classic from our coming teardown.

The best!

There is something to be said for the technology that you can adjust to fit your schedule. DH likes the bedroom freezing and the basic digital thermostat at the rental is either on or off at the set temp, so it runs all night long at a low temperature as there is no adjustment based on time. Can't wait for the zoned and fully programmable hvac.

Have you tried turning it off and on again?

Regarding retrofitting digital thermostats, especially wireless kinds, to older HVAC - the older units are not often compatible. You need a certain kind of wiring harness to be able to use the wifi thermostats. An extra wire missing from the older furnaces. We spent 30 years with a thermostat located too close to a heat run that went up the wall, so in the winter it would confuse the heck out of it. We finally go a new furnace & ac in 2020 and I was so excited to get a wireless thermostat! We finally got it better located. Well, until we installed our new gas fireplace, but at least I can put it in a different room until I turn the fireplace off. I need to find another new home for the bracket. New HVAC was long overdue. Love my thermostat too - I can change the temp while I’m away, or just in bed with an app on my phone! 😉

Batteries? That could be a good idea, easy enough to try.

As for that Honeywell dinosaur, say you don't mean it or we may have to arrange a mind reprogramming intervention on you. If you hear a loud knock on the door, that's what's happening.

"We've asked the real estate agent to see if the p.o. can at least tell us what brand/model it is."

I don't think the Post Office has anything to do with it.

(Saturday night comment)

Mark, what about police officers?

Purple Orchids ?

Purchase orders

Fuse burned out on the 24v side coming off the blower unit?

p.o. = Previous owner. It was a common abbreviation here at one time.

****

It's a Lennox iComfort Wi-Fi and the 26 page Homeowner's Manual doesn't provide the answer. If the "home screen" would display, I could probably figure out enough to have it work.

Since it's a well-cared for home with a 2018 furnace, AC and Aprilaire air purifier and the doctor owners only moved out a week before the closing, I figure the system was working. No mention of batteries.

**

Yes, I'd take the most basic thermostat available over this. (Just as I prefer my 17 year old pickup to any modern touchscreen controlled vehicle.) I bought the first generation iMac, so I'm not a technophobe!

@worthy At my old house, it was an in-line style automotive fuse. At my office, it is still an automotive style, but its on the circuit board in the blower unit. A couple of screws remove the cover to gain access

Maybe the thing is supposed to be hooked up to Alexa or something similar ... and you have to yell your hvac preferences! ;-)

Did you give up on the very modern house you were going to build?

Did you give up on the very modern house you were going to build?

After 21 months and eight tries, the grading plan passed. And we just shelled out another C$50K in fees to the City for the building permit, deposit and services. Now in the hands of the clueless licensed architect who, despite telling me everything was ready to go months ago, has received a list of deficiencies from the City.

Teardown Awaits! (Third temporary tarping mostly gone with the wind.)

We're readying a new temp home for move-in in two weeks. Whole other story!

The fact that the screen is blank leads me to believe the thermostat is not getting 24 V power. Is the the HVAC equipment in the attic? Is so there may be a power switch installed in the condensate overflow pan. If if the pan fills with water, the switch trips and cuts off 24 V power to the control board. This is a safety mechanism to prevent the AC from operating and causing water damage to the ceiling and the surrounding area.

We were all just being cheeky about the abbreviation 😉

The fact that the screen is blank leads me to believe the thermostat is not getting 24 V power.

Or any power because the furnace had been switched to "off". (Next I'll be complaining of my phone going blank.)

Isn't that the first troubleshooting step ... check that the appliance/tool/whatever is actually plugged in and switched on? 😄