Lennox Error Code E345: Relay O failure (Furnace)
Lennox error code E345 on a furnace means: Relay O failure. It is also called Lennox diagnostic code E345.
Homeowner? What Lennox code E345 means for you
Call a technician Your furnace is reporting: Relay O failure. The furnace has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.
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.
- Make sure the furnace front door or panel is closed properly; many furnaces will not run with the door switch open.
- Look at the air filter. If it is grey and clogged, replace it; a blocked filter causes many shutdowns.
- Outside, make sure the intake and exhaust pipes or vent cap are not blocked by snow, ice, leaves or a nest.
- Check that the gas valve next to the furnace is open (handle in line with the pipe). Do not force it.
- 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 E345 mean?
Listed in the 107045-XX table as an O relay failure; no action text given. The manual (including its troubleshooting section) gives no corrective procedure for this code; steps are general checks only.
Applies to: EL296UHV(X) series furnaces with integrated control 107045-XX only
Common causes of Lennox code E345
- O relay failure on integrated control
Lennox models that use code E345
EL296UH045XV36BEL296UH070XV36BEL296UH090XV36CEL296UH090XV48CEL296UH090XV60CEL296UH110XV48CEL296UH110XV60CEL296UH135XV60DSL280UH060NV36ASL280UH070V36ASL280UH080NV48BSL280UH080NV60CSL280UH090V36BSL280UH090V48BSL280UH090V60CSL280UH100NV60CSL280UH110V60CSL280UH135V60D
Other Lennox Furnace codes
All Lennox Furnace error codes →
Lennox code E345: homeowner questions
What does Lennox code E345 mean?
Relay O failure. Listed in the 107045-XX table as an O relay failure; no action text given. The manual (including its troubleshooting section) gives no corrective procedure for this code; steps are general checks only.
Is it safe to keep using my furnace with code E345?
It depends on the cause. The furnace has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.
Can I reset Lennox code E345 myself?
You can try one reset (power off for 30 seconds, then on). If Lennox code E345 comes back, the cause is still there and a licensed technician should check it.
Who can fix Lennox code E345 near me?
Aurora Star Tech Inc. repairs Lennox furnaces in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.
Homeowner help: Furnace Not Turning On: What to Check · Furnace Blinking Light: What the Flash Codes Mean
Troubleshooting guides
- Blowing cold air All brands · Furnace
- No heat All brands · Furnace
- Short cycling All brands · Furnace
- Blower motor does not run - Lennox SL280UHV ECM checks Lennox · Furnace
- Display shows two horizontal bars (soft disable) - Lennox SL297NV Lennox · Furnace
- Furnace will not run (no heat) - Lennox EL195UHNE Lennox · Furnace
- Furnace will not run (no heat) - Lennox SL297NV Lennox · Furnace
- Furnace will not run - Lennox SL280UHV checklist Lennox · Furnace
- Indoor blower does not run - Lennox EL195UHNE Lennox · Furnace
- Indoor blower does not run - Lennox ML180UHE Lennox · Furnace
- Poor ignition or combustion resonance - Lennox EL195UHNE Lennox · Furnace
- Poor ignition or loud combustion resonance - Lennox SL280UHNV Lennox · Furnace
- Two horizontal lines on display (soft disable) - Lennox communicating Lennox · Furnace
Source: Lennox EL296UHV(X) Unit Information / Service Literature, Ignition Control 107045-XX Diagnostic Codes table, p.44. 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.