Icon
Reliable Heating and Cooling Solutions – Quality Service, Fair Prices, Guaranteed Satisfaction!

Lennox Error Code E310: Discharge air temperature sensor problem (Air Handler)

Updated · by Aurora Star Tech Inc.

Lennox error code E310 on a air handler means: Discharge air temperature sensor problem. It is also called Lennox diagnostic code E310.

Medium severityAir Handler

Homeowner? What Lennox code E310 means for you

Check, then call Your air handler is reporting: Discharge air temperature 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 E310 mean?

Problem with the discharge air temperature sensor (DATS). S30/S40 thermostat alert code 310 (shown as E310 on the unit control display).

Applies to: Lennox communicating air handlers and EIM-equipped indoor units in S30/S40 smart thermostat systems

Common causes of Lennox code E310

  • Open or shorted sensor or wiring
  • Short/open in thermostat communication connections
Safety: Gas, electrical and refrigerant work must be done by a licensed technician. Turn off power and gas before servicing, never bypass a safety control, and always follow the manufacturer's manual for your exact model.

Other Lennox Air Handler codes

CodeMeaning
E180Outdoor temperature sensor problem
E201Blower motor communication fault
E202Blower motor and unit size mismatch
E203Invalid unit size code
E292Blower motor start fault
E295Blower motor over temperature
E312Reduced airflow - indoor blower cutback
E345Relay O failure
E346Heat pump jumper not removed
E347Indoor or EIM relay Y1 fault
E348Indoor relay Y2 fault
E350Electric heat not configured

All Lennox Air Handler error codes →

Lennox code E310: homeowner questions

What does Lennox code E310 mean?

Discharge air temperature sensor problem. Problem with the discharge air temperature sensor (DATS). S30/S40 thermostat alert code 310 (shown as E310 on the unit control display).

Is it safe to keep using my air handler with code E310?

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 E310 myself?

You can try one reset (power off for 30 seconds, then on). If Lennox code E310 comes back, the cause is still there and a licensed technician should check it.

Who can fix Lennox code E310 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

Source: Lennox Residential Communicating Systems Alert Code Guide (V2) 100017 (3/2023), Table 2 Alert Codes and Troubleshooting, p.25. 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.

Air Handler Emergency

647-657-2977