Not all Thetford RV toilets are interchangeable. There are several factors that determine whether a Thetford RV toilet is interchangeable, including the model, the mounting flange, and the plumbing connections. Thetford offers a wide range of RV toilets with different models and features, and each model may have different dimensions, mounting flange shapes, and plumbing connections. So, it is important to ensure that the replacement toilet you choose is compatible with your existing toilet's mounting flange and plumbing connections. Additionally, some RV manufacturers may use proprietary mounting flanges or toilet designs, which may limit your options for replacement toilets. In such cases, it is important to consult with a qualified RV technician or Thetford customer service to ensure that you choose the correct replacement toilet. In summary, not all Thetford RV toilets are interchangeable, and it is important to ensure that you choose a replacement toilet that is compatible with your existing toilet's mounting flange and plumbing connections.