No tank LED / off

Thetford Toilet: “No tank LED / off”

warning RV toilet warning lights

Safety Treat the circuit as live until you confirm it is off. House batteries can deliver very high current and cause burns or fire on a short — disconnect power before probing wiring, and do not bridge fuse terminals.

What it means

The tank-symbol LED is not lit at all. The toilet system is off or is receiving no power. The wall switch will not respond and the toilet cannot flush until power is restored.

Most likely causes

  1. Toilet circuit breaker or fuse is off or blown most likely
  2. Loose or disconnected power/ground wire at the toilet or control module common
  3. Dead or very low house battery / no 12V supply common
  4. Failed wall switch or control module rare

Safe checks you can do yourself

How to reset / clear No tank LED / off

  1. Restore power at the breaker/fuse.
  2. Cycle the breaker off for ~60 seconds and back on to reset the controller.

When to call a technician

Power and fuses are confirmed good at the toilet but the panel stays dark, indicating a failed switch or control module.

Applies to

Tecma Silence Plus 2G · Tecma Elegance 2G · Tecma macerating RV toilets with single tank-symbol wall switch

FAQ

What does Thetford Toilet code "No tank LED / off" mean?

The tank-symbol LED is not lit at all. The toilet system is off or is receiving no power. The wall switch will not respond and the toilet cannot flush until power is restored.

How do I reset Thetford Toilet No tank LED / off?

Restore power at the breaker/fuse. Cycle the breaker off for ~60 seconds and back on to reset the controller.

What is the most common cause of No tank LED / off on a Thetford Toilet?

The most likely cause is toilet circuit breaker or fuse is off or blown.

Related · Thetford toilet

Note: A dark panel only tells you there is no power/system-on signal; the underlying cause must be traced electrically.

Last verified 2026-06-29 · compiled from manufacturer documentation. Codes can vary by model year — always cross-check your unit’s manual.