Thetford 42178 Aqua-Magic Style II and Aqua-Magic Residence Seat and Cover Assembly - White

Thetford RV Aqua-Magic Style II and Aqua-Magic Residence Seat and Cover Assembly - White 42178

The Thetford 42178 Seat and Cover Assembly is a genuine replacement part designed for Aqua-Magic Style II and Residence RV toilets. This seat and cover provide a comfortable, stable, and hygienic surface while maintaining the original fit and appearance of your RV toilet.

If your existing seat or cover is cracked, worn, or discolored, installing the 42178 assembly restores a secure, clean, and comfortable seating experience. Manufactured to Thetford’s high-quality standards, this assembly is durable, easy to install, and engineered for a precise fit with compatible toilet models.

Upgrade your RV bathroom with the Thetford 42178 Aqua-Magic Style II and Residence Seat and Cover Assembly — an essential part for comfort, hygiene, and maintaining the aesthetics and performance of your toilet.

Features & Benefits

• OEM replacement seat and lid designed specifically for Style II & Residence toilets
• Bright white finish matches original factory toilet color
• Comfortable, ergonomic seat profile for everyday use
• Durable construction resists cracking, staining, and long-term wear
• Reinforced hinge system ensures stability and smooth lid operation
• Direct bolt-on replacement — installs easily using existing hardware

Fits These Models

Compatible with:

• Thetford Aqua-Magic Style II (High & Low Profile)
• Thetford Aqua-Magic Residence permanent toilets

Provides proper bowl alignment and hinge spacing for both series.

Common Issues Solved

Replacing with the 42178 seat assembly can fix:

• Cracked or broken toilet seats
• Yellowing, staining, or surface wear
• Loose or wobbly hinges causing unstable seating
• Mismatched or ill-fitting aftermarket seats
• Uncomfortable or hardened seating surfaces after years of use

Replaces / Also Known As

• Thetford 42178 Seat & Cover Assembly (White)
• Style II / Residence Toilet Seat Replacement – White
• RV Toilet Seat & Lid Kit
• OEM Seat and Lid for Thetford Permanent Toilets

What’s Included

• White toilet seat
• Matching white lid
• Integrated hinges (mounting bolts typically reused)

Installation Overview

1. Remove old seat by loosening the hinge bolts.
2. Clean the mounting area and bowl rim thoroughly.
3. Align new seat hinges with the bolt holes on the toilet bowl.
4. Insert and tighten bolts evenly for a secure fit.
5. Test seat and lid for smooth, proper movement.

Typical installation time: 5–10 minutes, using basic tools.

Frequently Asked Questions

Q: Will this seat fit Aqua-Magic Style Lite or Style Plus?
No. The 42178 fits only Style II and Residence models.

Q: Is this an OEM Thetford part?
Yes — it is the genuine factory replacement.

Q: Does it come with the mounting bolts?
Hardware is typically reused, but replacement bolt kits are available separately.

Q: Is the white color the same as the original toilet?
Yes — this seat matches the standard Thetford white finish used across Style II and Residence models.

Q: Can an RV owner install this without a technician?
Absolutely. The installation is simple and designed for DIY replacement.