Why some toilet seats are so awkward to replace

People expect a toilet seat to be the simplest spare part in the house. Then the new one rocks, leaves a gap at the front, or will not bolt down because the pan was never designed for a universal hinge.

The shape of the pan decides it

A round seat on an elongated pan overhangs or falls short. A D-shape pan — flat at the back, where a lot of modern close-coupled toilets are — needs a D-shape seat. If you put an oval seat on it, the china shows at the sides and the seat walks. Square and soft-square pans are their own family again. Look down on the pan. Buy that outline, not “white toilet seat”.

Some hinges are not hinges you can buy

• —Top-fix and bottom-fix are both normal. The bolts are a standard job.
• —Quick-release seats unclip for cleaning. The release button is often peculiar to that maker.
• —Soft-close hinges are damped. A cheap replacement may fit the holes and slam, because the damper was in the old hinge, not in the seat.
• —A few pans hide the fixing inside a shroud or a dedicated cartridge. A supermarket seat has nowhere to land.
• —Wrap-over seats on a rimless pan need the rim the seat was drawn for. Rimless does not mean “any seat”.

What we do on a refit

A new pan comes with a seat that belongs to it. That is the point of specifying the toilet rather than inheriting one. If you are only replacing a seat on a pan you are keeping, photograph it from above and from the side, and measure the hole spacing. If the seat is yellowed because the hinges have cracked the coating, the pan may be ready to go too.

Close-coupled or wall-hung toilets →