Said It Here

Why does my thermostat screen keep going blank?

A blank thermostat screen can be caused by fried internal wiring, such as a damaged W1 connection, even after trying new batteries and resetting the circuit breaker. Because diagnosing these electrical issues often requires specialized tools like a voltmeter, homeowners are left unable to troubleshoot the failure on their own when the unit intermittently shuts off.

What people tried

Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.

  1. 1
    Replacing thermostat batteries
  2. 2
    Checking condensate drain lines and float switches
  3. 3
    Calling an HVAC technician for professional diagnosis
  4. 4
    Flipping breakers and system switches off and on
  5. 5
    Inspecting internal wiring and control board terminals for visible damage
  6. 6
    Jumping wires with pliers to test system response

In their words

Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.

r/hvacadvice2 people · September 2026

I noticed last night that my thermostat was blank.source ↗

I did some trouble shooting such as replacing the batteries. Flipping the breaker off for 10 seconds then back on.source ↗

When opening the bottom part of the unit, I noticed that my W1 wire and connection seem to be fried.source ↗

InspectorPowerful370 · r/hvacadvice · 7 upvotes

My thermostat has been intermittently shutting off and going completely blank, then coming back on its own later with no changes on my end.source ↗

No_Benefit_4985 · r/hvacadvice · 3 upvotes

I don’t have a voltmeter to check, gonna have a buddy come check it outsource ↗

InspectorPowerful370 · r/hvacadvice · 1 upvotes

Where this came up

People with this problem also raised