Lennox Error Code –: Double dashes – zone sensor problem (Air Handler)
Lennox error code -- on a air handler means: Double dashes - zone sensor problem. It is also called Lennox diagnostic code --.
Homeowner? What Lennox code -- means for you
Check, then call Your air handler is reporting: Double dashes - zone sensor problem. This is often caused by something simple. Try the safe checks below; if the code returns, book a service call before it turns into a no-heat or no-hot-water emergency.
Safe things you can check yourself
- Check the thermostat: right mode (Heat or Cool), set a few degrees past room temperature, and fresh batteries if it uses them.
- Make sure the unit has power: its on/off switch (often looks like a light switch near the unit) is ON and the breaker in the electrical panel is not tripped.
- Look at the air filter. If it is grey and clogged, replace it; a blocked filter causes many shutdowns.
- Try one reset: turn the power off for 30 seconds, then back on. If the code comes back, stop resetting and call a technician.
Call (647) 657-2977Book a service call
Licensed technicians serving Vaughan, Toronto and the GTA.
What does Lennox error code -- mean?
Two dashes shown for indoor temperature on the S30/S40 or zone sensor: loose or miswired connections or two zone sensors on the same zone number. System runs central mode and individual zoning is disabled. S30/S40 thermostat / zone sensor display.
Applies to: Lennox communicating air handlers and EIM-equipped indoor units in S30/S40 smart thermostat systems
Common causes of Lennox code --
- Loose or incorrect zone sensor wiring
- Duplicate zone number
Other Lennox Air Handler codes
All Lennox Air Handler error codes →
Lennox code --: homeowner questions
What does Lennox code -- mean?
Double dashes - zone sensor problem. Two dashes shown for indoor temperature on the S30/S40 or zone sensor: loose or miswired connections or two zone sensors on the same zone number. System runs central mode and individual zoning is disabled. S30/S40 thermostat / zone sensor…
Is it safe to keep using my air handler with code --?
It depends on the cause. This is often caused by something simple. Try the safe checks below; if the code returns, book a service call before it turns into a no-heat or no-hot-water emergency.
Can I reset Lennox code -- myself?
You can try one reset (power off for 30 seconds, then on). If Lennox code -- comes back, the cause is still there and a licensed technician should check it.
Who can fix Lennox code -- near me?
Aurora Star Tech Inc. repairs Lennox air handlers in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.
Troubleshooting guides
- Two horizontal lines on display (soft disable) - Lennox communicating Lennox · Air Handler
Source: Lennox Residential Communicating Systems Alert Code Guide (V2) 100017 (3/2023), Table 2 Alert Codes and Troubleshooting, p.51. Written in our own words as a summary; always check the original manual.
General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.