ERR
Honeywell · TH6220D1028 FocusPRO 6000 2H/2C Programmable Thermostat
The thermostat is showing "Err" on the display indicating an internal hardware fault or sensor failure — this rare error typically means the built-in temperature sensor has failed or the internal circuitry is damaged; try removing the thermostat from the wall plate, waiting 30 seconds, and reattaching; if "Err" persists, the thermostat needs replacement
Error ERR on the Honeywell TH6220D1028 FocusPRO 6000 2H/2C Programmable Thermostat means: "Err" Displayed on Screen. The top-ranked community fix is “Replace Thermostat Temperature Sensor or Thermostat Unit” (hard difficulty, ~45 min, DIY cost: $10-$20). 2 community-ranked fixes available below.
Published February 2026 · 2 fixes · thermostat
Content is based on manufacturer service documentation, community repair experience, and OEM technical bulletins. Always verify with your owner's manual.Learn about our editorial standards.
While many thermostat repairs can be done safely at home, consider hiring a qualified technician if:
Average professional repair cost for this issue: $120-$200.
thermostat · 2 fixes
thermostat · 2 fixes
thermostat · 2 fixes
thermostat · 2 fixes
thermostat · 2 fixes
thermostat · 2 fixes
thermostat · 2 fixes
Thermostat Shows Offline in App
"Aux Heat" Displayed
Blank/Dead Display — No Power
HVAC Control Board Fuse Blown
"Cool On" Flashing on Display
"Em Heat" or Emergency Heat Mode
Fan Running Constantly
"Filter" Reminder Displayed
The Honeywell TH6220D1028 FocusPRO 6000 2H/2C Programmable Thermostat has 8 other known error codes:
Error code ERR also appears on 7 other Honeywell models:
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