Kohler Bidet E1 Error — Power Fault Fix Guide

What Does This Error Mean?

E1 on Kohler bidet seats indicates a power fault — the unit detected voltage outside the expected range.
Either the GFCI outlet has issues, the power adapter is failing, or there's an internal power supply fault.
Check the GFCI outlet first (press Reset).
If E1 persists, contact Kohler customer service — most fixes are power supply or controller replacement.

Affected Models

Kohler Numi 2.0
Kohler Veil
Kohler PureWash
Kohler C3-455

Common Causes

GFCI outlet tripped or failing
Power adapter degraded (output voltage out of spec)
Internal power supply circuit fault
Surge damage to power input section
Loose connection at the unit's power input

How to Fix It

Press Reset on the GFCI outlet.

Find the GFCI outlet the Kohler plugs into (usually on the wall near the toilet).
Press Reset.
If the outlet won't reset, the GFCI itself may have failed — call an electrician.
If it resets and Kohler powers up normally, monitor for E1 returning.
Power-cycle the unit.

Unplug from the GFCI for 60 seconds.
Plug back in.
Let the Kohler boot.
If E1 doesn't return immediately, monitor over the next few uses.
If E1 returns, the fault is in the power section.
Check the power adapter.

Some Kohler models use external power adapters (a brick on the cord).
Inspect the adapter — look for swelling, scorching, or unusual heat.
If the adapter feels hot or looks damaged, that's likely your E1.
Kohler can ship a replacement adapter.
Test the outlet with a different appliance.

Plug a known-working device (lamp, phone charger) into the same GFCI outlet.
Does it work normally?
If yes, the outlet is fine and the issue is in the Kohler.
If no, the outlet has issues — call an electrician.
Contact Kohler customer service.

Call Kohler customer service at 1-800-456-4537 (US).
Provide the model and serial number.
For warranty repairs, they may ship parts or schedule on-site service.
Out of warranty: 150-350 USD typical for power supply repair.

Frequently Asked Questions

Will my toilet flush with E1 active?

Yes — the toilet works normally regardless of bidet seat errors.
You'll lose bidet features (wash, dry, heated seat) until the Kohler is repaired.
The plumbing for flushing is separate from the bidet electronics.

Can a power outage cause E1?

Sometimes — a sudden power loss while the Kohler was running can stress the power supply chips.
If E1 appeared after a recent outage, that's likely the cause.
A small surge protector helps prevent recurrence.