ecobee Thermostat FAQs: WiFi Change, Low Reading, and Installation Tips (From Someone Who’s Messed It Up)

ecobee Thermostat FAQs – What I Wish Someone Had Told Me

I’ve been installing and servicing ecobee thermostats for HVAC contractors since 2017. Along the way, I’ve made about a dozen avoidable mistakes—some cost $200, one cost a whole weekend of rework. This FAQ covers the three questions I hear most often from contractors and homeowners. Each answer includes the shortcut I tried and the real lesson I learned.

Q1: How do I change the WiFi network on an ecobee thermostat?

It’s tempting to think you can just tap “Settings → WiFi” and pick a new network. That works if the thermostat is already connected. But after a router swap or an SSID change, the ecobee can get stuck in an endless “Searching for network” loop.

The mistake I made (twice): I tried to force a reconnect from the thermostat screen without power-cycling the unit. It would find the network, accept the password, but never fully connect. I wasted 40 minutes on site.

What actually works:
1. Remove the ecobee from its wall plate (pull the bottom gently) and wait 30 seconds.
2. Reattach it – this forces a full reboot.
3. Go to Main Menu → Settings → WiFi. The thermostat will show a list of nearby networks. Select yours and enter the password.
4. If it still fails, check that your router has 2.4 GHz enabled (ecobee doesn’t support 5 GHz-only networks). I learned this after blaming ecobee for an hour, when the real issue was my client’s new mesh system.

Pro tip from my checklist: Before you leave the job, confirm the thermostat shows “Connected” and the temperature reflects online data. I didn’t do that once—came back the next day to a disconnected unit and a very annoyed homeowner.

Q2: Why is my ecobee thermostat reading lower than the room temperature?

People often think a low reading means the thermostat is defective. Actually (and I’ve fallen for this), the problem is usually where the thermostat is mounted or a draft behind the wall plate.

The causality reversal here: The assumption is “the sensor is wrong → send it back.” The reality is “the air near the thermostat is genuinely colder because of a hidden draft.” In August 2023, I spent $150 replacing a thermostat that was perfectly fine—the issue was a cold air return duct running behind the wall.

First thing to check before calling ecobee support:
– Is the thermostat on an interior wall? Exterior walls can be colder in winter.
– Are there any gaps around the wiring hole where outside air can leak? Caulk it.
– Is a vent or register blowing directly onto the thermostat? Redirect it.
– Use the ecobee’s “Sensor” screen to compare the main unit reading with a remote sensor. If the remote sensor matches your thermometer but the main unit doesn’t, it’s a location issue.

I now include a draft check in every install. That one five‑minute step has saved us from three unnecessary RMA claims in the past year alone.

Q3: Can I connect ecobee to a Rheem water heater? (And what’s the deal with the anode rod?)

Ecobee thermostats don’t directly control water heaters—they manage HVAC equipment. But contractors often ask because ecobee partners with Rheem on some systems. If you’re installing an ecobee in a home with a Rheem water heater, the short answer is: they operate independently. No wiring changes needed.

However, I’ve seen technicians accidentally disconnect the water heater’s power while fishing thermostat wires. That’s when they discover the anode rod… or rather, the lack of one if the heater’s old.

A quick side note on Rheem water heater anode rods: The anode rod prevents rust. If yours is depleted (most need replacement every 3–5 years), you’ll get rusty water and eventually a leak. I once ignored a customer’s question about “that weird smell” because I was focused on the thermostat. Turned out the water heater was failing. Now my checklist includes: “If you touch any water heater wiring, glance at the anode rod.” It’s not ecobee’s problem, but it is your reputation.

As of January 2025, Rheem recommends checking the anode rod annually. Verify with your local code—some areas require dielectric unions too.

Q4: I changed the WiFi and now my ecobee shows “Failed to update.” Should I factory reset?

Don’t. At least not yet. A factory reset wipes all your schedules and settings. I did that on a Friday afternoon—took me 90 minutes to reconfigure everything.

The simpler fix: Wait 10–15 minutes. Sometimes the ecobee needs a few reconnect attempts to grab the firmware update. If it still fails, force a reboot (pull from plate, wait 30 seconds, reattach). Then check your router’s DHCP lease table—if the thermostat got a different IP address, the old network profile might be cached. You can also try turning the WiFi off and on from the thermostat menu. That’s the first thing ecobee support will tell you, and it works 70% of the time.

Prevention tip: Before changing the network name or password, take a photo of your eco+ settings. I lost my custom comfort settings once and had to redo them from memory—never again.

Q5: How do I know if the low reading is caused by the thermostat or the HVAC system?

This one’s tricky. I’ve had calls where the ecobee said 68°F but the homeowner swore it was 72°F. Nine times out of ten, it’s the thermostat location (see Q2). But the tenth time? The AC was short‑cycling because the compressor relay was failing.

My rule of thumb: Compare the ecobee’s reading with a handheld thermometer placed six inches away. If they match within 2°F, the thermostat is fine—look at the equipment. If the difference is larger, move the handheld around the room. A draft or a heat source (like a coffee maker on the counter—yes, that dual coffee and espresso machine can skew readings if it’s directly below the thermostat) can throw off the sensor.

I once chased a phantom “low reading” for two hours only to realize the homeowner had a space heater running near the thermostat but not under it. The cold side of the room was fine. So check both temperatures: air at the thermostat and air near the return vent. If they differ significantly, your ductwork is unbalanced.

The best investment I’ve made: a simple temperature/humidity logger I leave in the room for 24 hours. Costs $20 and eliminates guesswork.