Thetford Toilet Lip Seal Replacement for Cassette® C2 Electric & Cassette® C4 Permanent Toilets - 23721

Thetford Toilet Lip Seal – Replacement for Cassette® C2 Electric & Cassette® C4 Permanent Toilets

The Thetford Toilet Lip Seal is an OEM-correct replacement part designed to restore a tight, hygienic seal in Thetford Cassette® C2 Electric and Cassette® C4 permanent toilets. This single-piece lip seal installs at the cassette waste opening to help prevent leaks, control odors, and ensure smooth blade operation.

Replacing a worn lip seal is one of the most effective maintenance steps for keeping your cassette toilet clean, reliable, and odor-free.

Key Features & Benefits

• OEM-Correct Replacement – Manufactured to Thetford specifications for proper fit
• Improves Odor Control – Maintains a tight seal between bowl and cassette tank
• Helps Prevent Leaks – Replaces hardened, cracked, or worn seals
• Smooth Blade Movement – Supports proper opening and closing of the blade valve
• Durable Seal Material – Designed for frequent use and sanitation chemicals
• Simple, Cost-Effective Repair – Extends the life of cassette toilet systems

Fits / Compatible With

• Thetford Cassette® C2 Electric Toilet
• Thetford Cassette® C4 Permanent Toilet

Not compatible with Porta Potti®, Campa Potti®, or Aqua-Magic® models.

What’s Included

• (1) Thetford Toilet Lip Seal

Specifications

• Seal Type: Lip seal
• Application: Cassette toilet waste blade sealing
• Quantity: Single
• Brand: Thetford

Common Issues This Seal Solves

• Odors escaping from the cassette toilet
• Moisture or waste seeping past the blade
• Stiff or uneven blade valve movement
• Degraded, flattened, or hardened seals
• Poor sealing between bowl and cassette tank

Installation Overview

1. Remove the cassette tank from the toilet
2. Access and remove the worn lip seal
3. Clean the sealing groove thoroughly
4. Install the new lip seal evenly
5. Lightly lubricate with RV-safe silicone lubricant
6. Reinstall cassette and test blade operation

Frequently Asked Questions (FAQ)

What does the lip seal do in a cassette toilet?

The lip seal creates a flexible barrier between the bowl and the cassette tank, preventing odors and leaks while allowing the blade valve to operate smoothly.

How do I know when the lip seal needs replacement?

Common signs include persistent odors, moisture around the blade opening, or stiff blade operation.

Is this an OEM Thetford part?

Yes. This seal is manufactured to Thetford OEM specifications for correct fit and performance.

Should I lubricate the seal after installation?

Yes. Applying a silicone-based, RV-safe lubricant helps extend seal life and improves blade movement.

How often should cassette lip seals be replaced?

Replacement intervals vary by use, but many owners replace the lip seal every 1–2 years or whenever signs of wear appear.