Lennox SLP98UHV Error Code E 113: High Line Voltage
What Does Code E 113 Mean?
Error code E113 on the Lennox SLP98UHV means the incoming line voltage is higher than the unit's nameplate rating. The SureLight control monitors the 120V supply and flags E113 when it climbs above the safe operating range.
High line voltage is usually a utility-side problem — the power company delivering excessive voltage — but it can also come from a failing neutral connection in the home's electrical system, which lets voltage rise on some circuits, or a faulty utility transformer serving the home. E113 is part of the power-quality family with E110 (line voltage too low) and E114 (line frequency not 60 Hz), all of which watch the 120V line; E115, by contrast, watches the separate 24V transformer secondary.
High voltage is generally more damaging than low voltage: it can quickly burn out the control board, motor windings, and other sensitive parts. The SLP98UHV's variable-speed motors and communicating electronics are especially vulnerable. An electrician should measure the voltage at the furnace and at the main panel and contact the utility if it is consistently above the acceptable range.
What You'll Notice
- E 113 shown on the furnace control's 7-segment display
- The furnace shuts down or refuses to start to protect its electronics
- Light bulbs elsewhere in the home burn out unusually often
- Other appliances or electronics behave abnormally or run hot
- The code coincides with known utility power problems in the area
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Utility power supply delivering excessive voltage | Most common | ✗ Call a pro → |
How This Is Diagnosed
E113 is a supply-quality fault, so a technician or electrician measures the incoming voltage rather than swapping furnace components. The voltage is read at the furnace disconnect and compared to the nameplate rating to confirm it is genuinely high.
The reading is then repeated at the main panel. If both are high, the source is the utility service and the power company must correct it. If only certain circuits read high, the electrician suspects a failing neutral connection in the home's wiring, which requires prompt repair because high voltage can damage electronics throughout the house.
When to Call a Professional
This code involves components that are not homeowner-serviceable, so have a licensed HVAC technician diagnose and repair it. Keep in mind:
- Promptly — sustained high voltage can damage the furnace's control board and motors
- An electrician needs to measure the voltage at the furnace and at the main panel
- Light bulbs burn out frequently or other appliances behave abnormally
- The utility company may need to be contacted about an over-voltage supply
Frequently Asked Questions
Why is E113 more urgent than the low-voltage code E110?
Over-voltage tends to damage electronics faster than under-voltage. Because the SLP98UHV's control board and variable-speed motors can be harmed by sustained high voltage, E113 is worth diagnosing without delay.
Could this be caused by something in my house rather than the utility?
Yes. A failing neutral connection in the home's wiring can push voltage up on some circuits. Measuring at the panel and comparing circuits is how an electrician tells a home wiring fault from a utility over-voltage.
Should I turn the furnace off until it's checked?
Leaving it off avoids running the electronics on unsafe voltage. It is reasonable to switch the furnace off at the breaker and have the supply checked, especially if other appliances are also affected.
✓ Verified against manufacturer service manual — March 2026